Originally Posted by
oliver2002
Think about the reverse situation: if a EU citizen would show up at the US border and say that s/he owns property in the US and plans to marry a US citizen in June. What would happen?

Thanks for the laugh

, but the situation is a little more beneficial for the OP. The "normal" way for a U.S. citizen (and citizens of a few other privileged countries as defined in §41 AufenthV) to immigrate to Germany is to come as a visitor and apply for a residence permit from inside Germany. They do not have to cross the German border with the correct immigrant visa, as would be the case in the U.S. So in pre-Covid19 times, this would have worked just fine.
The only question is, whether it still works with covid19-inspired travel restrictions in place.