I doubt Trump intends to keep the tariffs up for long (at least not with Canada, and probably not MX).
Again, I'm certainly not an economist, but you don't have to be to understand how Trump thinks. Some people show you the stick and show you the carrot and let you decide which one you want. Trump's style has always been to bludgeon you with the stick first, then offer you half a carrot. Sure, you'd rather have the whole carrot, but you'll take half if it means he stops hitting you with the stick.
My guess is he quickly renegotiates some stuff with Canada and MX, ends the tariffs, claims a victory, and moves on to something else.