The chances of Henry Curthmantle or Henry Plantagenet (the future Henry II of England) would be elected King of Germans seems zero since he's unrelated to Henry V, Holy Roman Emperor and King of Germans and he's not descendant of any of the major German noble dynasties.
However much later, the electors considered a successor to Maximilian and they included Charles von Hapsburg (the future Charles V), King Francis I de Valois, and Frederick of Saxony. The fact that Francis is in the list of consideration means the idea of a foreign king isn't out of the question.
So let's say he becomes part of the consideration (somehow...) and several decades later when the current emperor dies he somehow wins the election. Yay, he's now in charge of England, Normandy, Anjou, and Germany while his wife has Aquataine!
Except that after sitting in England and Normandy for so long he decides that what he wants to do is ensure the future for his children in his possessions around the Channel, the Anvegin Empire (not that he would have called it that, I think the term first arose by chroniclers in Edward II's time). So the only thing he wants out of the emprorship is to keep Germany stable, catholic, keep rural lords more powerful than the city ones, and get money without alienating everyone.
So... how to treat the Kingdom of Germany as a piggy bank for Normandy without triggering a revolt? Richard the Lionhearted had the excuse of "well, I need this money for a Crusade, you know the Lord calls"