As a Canadian, I hear frequently from Americans that Canada is a homogeneous place. I imagine there are a lot of different ways to measure that, but for what it's worth, per StatsCan Canada has the highest foreign-born population in the G8[1]. Subjectively, Toronto feels amazingly polyglot compared to most large US cities I've spent time in. (Although, as in the US, there's a lot of geographic variation.)

Not to invalidate your point, but that particular assumption always strikes me as dubious.

1. https://www12.statcan.gc.ca/nhs-enm/2011/as-sa/99-010-x/99-0...