In 1637 Elisabeth Stuart, mother of Rupert of the Rhine, tried to arrange his marriage to wealthiest Huguenot heiress of France, Marguerite de Rohan (who later married morganatically to Henri Chabot, founding Chabot-Rohan family).
http://en.wikipedia.org/wiki/Marguerite,_Duchess_of_Rohan
In OTL Marguerite declined the marriage to the son of exiled "Winter King", but WI she agrees? She was the person to marry for love (see her OTL marriage), so what if she finds Rupert hot and decides to disregard that he's landless and impoverished (hell, it worked for Rupert's younger brother Edward).
The most direct butterfly will be no Linz imprisonment? But how Rupert becoming
juro uxoris Duke de Rohan and Prince de Leon will affect the final stage of Thirty Years War, the English Civil War (will it be as drastic as say removing Cromwell?) or even Fronde?
Not to mention the legal and totally non-morganatic Rupertine line of Palatinate-Simmern Wittelsbachs (direct male descendants of Marguerite de Rohan are alive now, there are also living descendants of Ruperta Howe, so no Palatinate succession crisis?).