You can totally get by in Montreal speaking English only.
Here’s the CEO of Air Canada, Michael Rousseau, on how he’s managed to thrive in Montreal without knowing French working for a legislatively bilingual organization: https://www.cbc.ca/news/business/air-canada-ceo-1.6393063
> Even if you could work remotely, why would you move somewhere you don't speak the primary language
Immigrating to Quebec from outside of Canada is difficult since they have a system to keep non-French speakers from moving there.