I am born and raised in Montreal as an anglophone. There are many companies in Montreal that are run by English speakers and so the work environment tends to be English. I would say that if you don't speak French, you shouldn't bother with a French CV. Big companies are usually accustomed to having to switch back and forth between languages. If you are applying to smaller companies, you can usually tell by their website which language they work in. An English website usually means an English work environment!
All of this to say that each company is Montreal will have their unique way of working with language. Just like you look to work for a company that fits with your values and career goals, in Montreal you also look for a company that fits with your language abilities and preference.
Hope that was helpful!