With any POD after 1945 up until 1955, have East Germany, meaning that there must be a West Germany as a counter, be larger then it was OTL. Possibly to its greatest extent.
It seems like you're using "resp." in the way Germans would use "bzw". I find that funny, especially since I can't see anything wrong with it, just that I've never seen "respectively" used that way before.That's why the areas east of the Oder-Neiße are given back resp. not annexed by the Polish resp. Soviet states. Thus the GDR would be about 150.000 km² instead of 108.000.