I get the feeling that there is a slight difference in meaning though, that "in the winter" and "på vintern" implies a habitual that is made each year, whereas "for the winter" implies a probable one-time trip somewhere. Do you agree?
To me (Australian English) "in the Winter" means any time within that season, while "for the Winter" would mean the entire duration of that Season.
Haha, I posted this exact reply but it didn't post as Duolingo was down for some time i believe.
I agree 100%
So the question is.... Is the preposition på used for both of the above english translations?
No, 'for the winter' would have to have a different translation. The best option is probably över vintern.
Really? Doesn't overseas necessarily mean crossing a large body of water?