I've lived in ID and MT (bordering BC and Alberta) for most of my life and people mostly say canadian geese even though I've heard that canada geese is preferred.
I agree. I only have ever had one person correct me on this, who was, incidentally, Canadian. It's rather infuriating because the Latin name is literally 'from Canada'...which we already have a term for(Canadian). If anything, it feels like Canada Goose is a bad translation that people stick to.
[0] https://en.wikipedia.org/wiki/Canada_goose