On 21 December, the day is about 77 minutes longer in Miami than in NYC, and panels in Miami aren't going to be covered in snow.
> Can you create a long distance transmission line from New York to Brazil?
Yes. $$$.
Spend enough (production is high enough for this, yes I have checked, it's just how much money you want to spend) and it could be from NYC to Perth Australia.
> Even if you could in theory, probably not in practice, and even regardless of the technical factors nobody is going to want that kind of cross-border dependency for something as important as heating.
Also true. Unfortunately.