Do the vassal duchies of Courland and Prussia come along?
Just to make a point:
Although the high water mark of the Reformation has passed and several magnate families have (re)converted to Roman Catholicism, the PLC is not as Roman Catholic as it will become later. Not having subsidies/bribes from Habsburg neighbour/ally will change Counter-Reformation dynamics.
And the PLC is much more Orthodox than it will become later. There had been an Union in 1596, true, but it really took off in the XVIIIth century when the Orthodox Church in the PLC was transferred from the Ecumenical to the Moscow Patriarchate.
This is an economic disaster, with all export markets now being across the ocean. And not all commodities can be exported by sea, e.g. live oxen.
Speaking of sea transport - the Vistula, Niemem and Dvina draining into the Great Lakes makes the economic disaster even worse - now there is no way to export high volume and weight goods like grain and naval stores. Maaaybe the Warta drains into the Missouri/Mississippi which would then allow - with extensive canal building - the restoration of such exports, now through (ugh! eww ... ) New
Orleans Gdańsk. The canals will need, naturally, time, money and know-how. Before - if ever - commercial ties are recreated DECADES may be expected to pass. In the meantime - good luck!
The Dneper draining into the Atlantic is practically useless due to the rapids. I imagine the Dnestr basin becoming much more attractive, though. Anybody know how navigable it is? It passess through the same rock formations as the Dniepr ...
PLC Westward expansion? Actually - in all directions
Quite likely. But with the PLC being as anarchic as it was - would the newly occupied and settled lands pay heed to Warsaw and Wilno?
With no Tartars and Turks around I expect the Zaporozhe Cossaks to break away. The devastated PLC will be incapable of reining them in. Also their location - note to non Slavic folks, the name Zaporozhe means Beyond (i.e. below) The Rapids - will privilige them in contacts with the Maritime Powers. Leaning towards Orthodoxy the Cossaks will probably be more open towards the Prots, i.e. the United Provinces. England is poor and primitive, and the less said about Scotland the better.
In Europe the Free Clay has a strong contender in Sweden. Instead of (or alongside) attempts to steal Ancient Russian Clay like Karelia it will have lots of juicy, empty (Amerindians do not count to European rulers) land.
Brandenburg will be delighted too
Russia is having its Troubles which - with no PLC adventurers - may be overcome faster here. Or maybe not - with no need to unite against the PLC and Sweden (Sweden busy in the new clay) the infighting may continue for longer.
Tartars lose part of their slave raiding grounds - either switch to more raiding of Muscovy - maybe Moldavia and north Caucasus - or face economic hardship.
The 1683 siege of Vienna is too far to be relevant. The Thirty Years War will be different enough as to trash bin the OTL.