Others can comment with their experience but my guess was informed by recent job searches and forums, albeit not for this title. Doing a search right now for a Staff Engineer in Toronto seems to hint at 180 - 200K CAD being the upper limit.
You are an outlier and only because you work for an American Company that pays you what they might pay locally in SF. Perhaps they don't know they could pay you 1/2 of that easily....
Taxed once. I work for a SF company that has set up a Canadian arm of the business.
Despite all that, it’s a bargain compared to Bay Area pay.