We could easily deafeat Canada.
Canada only has 35 million people. The USA has 314 million.
80% of the Canadaina population lives within 60 miles of the US border.
Don't confuse military superiority with the ability to defeat someone. We have been through that before.
The people who live out in the boonies would be a lot more labor intensive than the city folks.
All silliness aside, considering we import more oil from Canada than the Saudis, I think it is to our mutual benefit to keep things friendly.