I live in Montréal too and I'm chiming in that it's easy to live here with only English, 25% of the city is natively anglophone. Some people in the company I work at (also immigrants) see no reason to learn French, which the quebecois probably don't want to hear.

It is easy to get the hang of signage too; lots of French words are spelt almost identically in English, and the language is much easier to read than it is to listen to. You should get the hang of it quickly.

On the other hand, if you have to get any kind of job that involves speaking with customers ... you are shit out of luck.