If the goal is to have Hungary be independent, and not in personal union with another monarch, then maybe a Bourbon?
I don't really think a Bourbon is that plausible.
An Orleans monarch perhaps?
I sincerely doubt it, if Louis XV is like his OTL counterpart, this was the point when he refused Chartres' marriage proposal to his daughter, Anne-Henriette, due to the fact that he didn't want the house of Orléans anywhere near as powerful as it had been under the Régence
Yeah with Louis XV I doubt the Orleans will get a crown.
As a counter to Etri, bad idea, as the Saxons were also Kings of Poland-Lithuania. A terribly and irreversibly declining King of Poland-Lithuania, but King of Poland-Lithuania nonetheless. And bulwark or no, I don't think either Prussia, Russia, or even whoever sits on the Imperial throne (Bavaria more or less) would want a strong (or moderately so) Poland-Lithuania-Hungary-Saxony next to them. That's just looking for trouble.
Now, as for a native dynasty, don't need to have a blood relation to the King of Hungary (in fact, none of them technically do) but you also have to take to consideration, in the event of critical failure of succession, the nobles did once upon a time elected a noble to sit as King of Hungary (see the Zapolyas) So theoreically, any native dynasty has a shot provided they get the support from whatever Hungarian nobles are around.
I agree that the Saxon option has problems but I don't think those are the ones. Russia as nonparticipant has no say in who is King of Hungary. Meanwhile the Bavarians due to the fact that French armies just delivered Austria and Bohemia to them can't complain about Hungary. Whilst the Prussians after all their betrayals are in no position to protest especially with the French armies so close in Bohemia and Austria. In fact the Prussian king at this time was not plotting to against the Commonwealth and instead was so afraid of Russia that he would stop at nothing to lessen their threat to him. The real problem with the Saxon choice is the Hungarian nobility who might not take kindly to it.
Do you have any native candidates in mind, like the leading Hungarian families.
If i wanted to i could argue that Hungary was an independent kingdom in 1740. It was true that it had been for a long time in personal union with Austria and by the acceptance of the Pragmatica Sanction it accepted a bit more than that. But the Habsburgs had rights in Hungary as the Kings of Hungary. Them being the archdukes of Austria or Holy Roman Emperors gave them nothing. I also want to point out that every Habsburg ruler of Hungary had himself crowned the King of Hungary with only one exception - and that led nearly to rebellion.
It was more than one occcasion that the nobles have chosen a local noble as the king of Hungary. So I think if Hungary breaks away most likely the local noble who led the rebellion would end up as ruler.
I would be interested in a POD were this happened as Maria Theresa enjoyed the undivided support of the hungarian nobility - what changed this? My idea would be that something went wrong during the reign of his father Charles. Maybe a harsh punishment that still must leave them strong enough to try it again aftrer the Rákóczi rebellion and a remaining hostility between the dinasty and the nobility could lead to this. But seeing how Charles didnt spare every effort to secure the sucession of his daughter i cant really believe that he wouldnt make peace with the Hungarian nobility.
Another possibility would be that the Habsburg loose the sucession wars so badly that Maria Theresa is left with nothing but Hungary in the end thus making Hungary de facto independent.
If it mustnt be a Habsburg or a local noble:
At the time the Hungarian nobility was mostly catholic so i think a catholic ruler who could bring some meaningful alliance. If not catholic than reformed. In both cases someone who isnt already the ruler of some other country.
Hungary was independent in some senses and not in others aand they did their own chancery, but they still along with the rest of the Hapsburg Empire were subject to the Imperial Council that was centered in Vienna and operated mainly by Austrians. But all of this really just unimportant semantics.
Anyone in mind?
Maria Theresa definitely had wide support among the Hungarian nobility as seen with their insurrections in which they rose tens of thousands of soldiers to support her reign. But I need no early POD to break off Hungary. Instead Hungary is granted its freedom by the victors (France) after the absolute destruction of House Hapsburg as a result of the War of the Austrian Succession. And to solidify that I have Maria Theresa not long outlasting her family's empire. Thus the Hungarians are somewhat forced by circumstances to abandon the remnants of the Hapsburgs for their own self interests.
That is something else I've considered and remains a possibility for what I'll do. And there could be a interesting situation that emerges after Maria dies and Joseph and Charles Joseph are left to duke it out.
Sounds reasonable.
What about a republic being declared? I'm not talking a modern republic with complete suffrage but sort of a government of the aristocracy were the head of state is merely primus inter pares and real power lay with the Hungarian Diet, obviously dominated by the aristocracy where they have broad reaching rights. Sort of a scenario where the aristocracy keep their current rights and possibly win back older ones abolished by the Habsburgs.
As for a King... maybe one of the sons of Frederick Augustus II, King of Poland and Elector of Saxony? Bonus points: they're Catholic, and secondly, the would-be King is young (the second son would be 10 in 1740, or it can go even younger), giving the Hungarians a chance to reign during a regency and shape their future king into the perfect roi fainéant. Considering how little the Saxon kings meddled during the time they held the Polish crown, they could be an attractive choice.
I don't think a republic is possible, but you are correct to assume that in this new Kingdom of Hungary the Hungarian nobility would hold much sway. For them to not would doom whoever is king.
Frederick Augustus II came much much later, I think you mean Augustus III, whose rule is recalled for its lack of rule. And yes you're right they were young at the time meaning that a regency would be in tow, so I see that as a strong possibility for king.
What about the eldest son of Francis II Rákóczi and Charlotte Amalie von Hessen-Rheinfels? I can only find this mention in the French Wikipedia:
George/György Rákóczi (1701–1756), fils du précédent. Il meurt en France en 1756.
If he is already living in French exile, he might be willing to be placed as a French client on the Hungarian throne.
I feel as if a Rakoczi wouldn't be accepted by the Hungarian nobility who didn't support his father's rebellion. Instead they saw it not as a Hungarian rebellion, but as a peasant rebellion. And the nobility's approval is key to the success of this new Hungarian monarchy. Meanwhile during his father's rebellion I don't think his father actually ever proclaimed himself king, so there's that. All in all the Rakoczi's don't seem like a good choice.