Originally posted by
kasumigenx
The Upper Silesian and Mazovian Piasts were the obvious contenders aside from the Luxembourgs after Louis I of Hungary died and one of them is a possible husband to Jadwiga until Jogaila came along, in OTL Jogaila married his sisters to the Upper Silesian and Mazovian Piasts to establish good relations with them - this silenced them and made them not to try to do something against Jogaila.
You mean Siemowit IV of Masovia. Indeed, a serious contender, but in XIVth century. However, partitions started almost 400 years later, with Jagiellon dynasty and a whole bunch of eleced kings in a way - and IIRC a Silesian Piast was never a serious candidate then.
The Duchy of Teschen was given to the Wettins(descended from the rulers of Poland-Lithuania) as a fief and later as an Appanage of the Habsburg-Lorraine - the question is if can any one of them recreate the Duchy of Warsaw?
You're right about a Wettin being in XVIIIth century duke of Teschen and a vassal of Austria. However, Albert Casimir Wettin, duke of Teschen, died in 1822, childless; the duchy returned then to Habsburg family (archduke Charles, to be exact).
Even if Albert Casimir had children, they still would have been vassals of Austria and any attempt of their part to create a Polish Piedmont would be stopped quickly and ruthlessly by Austria, with Russian and Prussian help, if necessary.