It’s just the beginning is my guess. If BYD or CATL commits to a factory /assembly in Canada I would expect limits to be raised on this as progress is made. Or if this goes well we could see limits raised as China drops Canadian product tariffs further.
The current (or next) admin would take Alberta and Saskatchewan. They'll propose that the residents secede from Canada and join the US.
There's probably enough political willpower in these provinces and money (paid by the US) to turn this into a real movement.
And from there, Yukon and the Northwest Territories are easy next dominoes.
My gut reaction is there is no way China is setting up vehicle manufacturing or assembly in Canada because the American President would go absolutely nuts. Canada is increasing ties and joint ventures with Canada but manufacturing would be a bridge too far for our little man in the White House.