Very Rough possibilities as I see them, including possible points of dispute.
First off, Saxony; The darker Green is what they had as a state inside the Confederation of the Rhine. Given that Bavaria was able to keep most of their territory except for Tirol and Salzburg, basically the areas they had a dispute with one of the presiding Great Powers over, I expect much the same would happen here, except Austria had a previous claim to those lands while Saxony is largely composed of territory it had before this whole Napoleon thing started.
The Paler Green near Saxony are some of the smaller German States that I could see being Annexed into Saxony itself as a reward for their service capturing Napoleon in the possibility I put forward earlier. I would say that Dark Green + Paler Green is probably the largest Saxony you could get using the timeline I put forward. Any further expansion of Saxony would have to be at the expense of either one of the other Major States.
If Bavaria had not defected along with Saxony you might see them lose some territory, but it will only be small bits in the former Würzburg area. Taking anything more from Prussia would either cut them off from Silesia, or have Saxons knocking on the door of the Berlin Gates. I do think that Russia and Britain will push hard for Prussia to not Lose any significant territory, and so I think it is most likely they will simply leave the council with a confirmation of the Borders resulting from the Treaty of Tilsit.
One possible point of dispute is Posen, which is why I have it dual colored. Russia will want it, they wanted it historically, but Prussia will also want it. It could be used as a wedge to drive apart Prussia/Russia in the conference to ensure that Russia is willing to see Prussia receive nothing.
Hanover also gained more territory, having received even more of the Kingdom of Westphalia since Prussia isn't there to take any of it. I'm not sure how much more they could get, as it is in no one's interest to give Britain such a major satellite state on the Continent, not even Britain's.
And the big thing that would need to be decided is what to do with the Rhineland. Which is a Pain because much of it was composed of
Prince Bishoprics which we're dismantled in the German Mediatization. In our Timeline they were not restored, but in this one they might unless there are some other Dynasties kicking around that land could be given to which I am not aware of. This is actually one of the possible benefits of expanding Saxony, as it would free up some minor noble houses who could be given small states in the Northern Rhineland.
Giving all of the Rhineland to Austria would make Austria a beast, and I don't think that is likely to happen. The current map is a bit of wishful thinking although I did let Hessen keep the chunk of the Rhineland they had before the congress. Likewise, I do not think that the territory will be divided up so all of the Victorius German States get a small slice, that would just make the defence uncoordinated and divided. If the congress decides to do something like that I think it is more likely to create a United Military Command under Austria which is responsible for garrisoning the Rhineland which the other German States are required to help support.
There's also the problem of Luxembourg, as if it is Austria getting the Rhineland to be a wall against France they may push for Luxembourg, as they do have the strongest Claim to it. If so, then I would say that the Entire Rhineland Buffer zone would likely shift southward. Bavaria will keep the Palatinate, but much of the rest will go to Austria. However parts of the North may be broken off and given either to Hanover, or to some of the Princes Displaced by a possible Saxon Expansion. Thoughts?
And then everything else is white because I don't know what might happen. I think Scandinavia will probably turn out the same way it was in OTL, but Italy could be radically different. If Austria is getting all of this extra German Territory it is very possible that they may not be getting as much Italian Territory.
