To get to Buffalo, you have to cross all the "width" and most of the "height" of New York State. To get to Montreal, it's just the "height" part plus an hour or so past the border.

Definitely use Google Maps to explore distances between cities, and find best routes.

It's pretty hard to not like Montreal, especially in the summer. Just For Laughs is on now. The city has a heavily funded tourism bureau; call to get more info and ideas.

As for language, I've been to Montreal twice: I never met anyone who didn't speak English well. The few times I tried to speak French, haltingly, the reply was in English anyway.