"Open the door to Chinese EVs" isn't a simple solution because it has wider reaches than restricting Tesla-imports. There's a reason Germany just effected tariffs on chinese EVs, namely because they are arguing that as china subsidizes their EVs, naturally non-subsidized local companies could never be price-competitive.
I don't know how that situation is in canada, but I bet similar things have to be looked at.
But given that a lot of these are US companies working in Canada, maybe that's for the better. I'm not Canadian so my opinion is irrelevant anyway. Likely some people will lose their jobs and that sucks.
Interesting wiki, I had no idea you produced so many cars, since I don't know of any major Canadian car brands I just assumed you didn't build any either, never thought there could be plants from foreign brands.