According to Philip William, Elector Palatine's German wiki article, before he married Princess Anna Katarzyna Konstancja of Poland-Lithuania, a possibility was booted around of him marrying Luise Charlotte of Brandenburg, OTL Duchess of Courland.
Interestingly enough, another husband proposed (as early as 1637) for said Polish princess, was Archduke Ferdinand of Tyrol (who married Anna de Medici, OTL). Anna Katarzyna Vasa's childbearing was reportedly ruined by the difficult birth of her stillborn son in July 1645. And if she bears Ferdinand a son, suddenly a the Hapsburgs have a claim to the PLC, meaning a possible non-Imperial Hapsburg Poland (IDK, I'm just putting the idea out there).
Now, what if both alternate marriages had come off, leaving the duke of Courland to find another wife.
Interestingly enough, another husband proposed (as early as 1637) for said Polish princess, was Archduke Ferdinand of Tyrol (who married Anna de Medici, OTL). Anna Katarzyna Vasa's childbearing was reportedly ruined by the difficult birth of her stillborn son in July 1645. And if she bears Ferdinand a son, suddenly a the Hapsburgs have a claim to the PLC, meaning a possible non-Imperial Hapsburg Poland (IDK, I'm just putting the idea out there).
Now, what if both alternate marriages had come off, leaving the duke of Courland to find another wife.