US passport is a definite plus, IIRC you do not have to go with the rest of the arriving packs through Canadian immigration, when you get to do the Canadian / US passport holders.

I am very impressed that you can do self-transfer with checked luggage in 2 hours, so you may well be able to pull it off here as well. I'm just leery of doing something like that on separate tickets .....

I did it pre-covid on a flight from US connecting to Asia, and I was sweating bullets with a 3-hour connection with only hand luggage, but that's me