I think Trump is severely misreading his position in the world. It's not April 2025 anymore. There will be consequences for everyone, but I am not sure his own party will support him through this in an election year. Especially now as the last time he publicly stated he backed down because if rising bond yields, which is actually happening already before any trade war. Is he really going to start another one, already in deep trouble because of the mess he made in Iran.
I think he will cave pretty quickly and Canada knows it.
I think they'll support him through the election. If the election goes as bad as it seems likely to, that might upset the apple cart. But it's also possible that it won't, and the Republican party will just be an empty discredited husk when Trump leaves the stage a couple years later.