Today's Mosport-CTMP-whatever has all the asphalt runoff, but not the garages and F1 facilities they lust for.
Mont-Tremblant is Grade 3 so they couldn't race on that even if they wanted. It is my second favorite track in all of North America though, so it was always sad not to have even the regional series there. Even Grand-Sham stopped going to that awesome place. Now the only non club/historic series returning per year is Ferrari Challenge NA, which doesn't get any coverage anyway so basically there is nothing.