consider this first
usa has aprox 10 times the population as us
nfl has only 4 time the number of cfl teams
usa is way more densely populated
now, before you put forth a name for cfl expansion, you need to look at the following.
take the five teams with the least population within 1 hrs drive of the stadium. Average those populations.
now considering that the average nfl game has 2 - 3 times more fans in the seats, cut that average population in half.
so, does your suggested city or town have within 1 hrs drive, 1/2 half the population of what the average of the 5 lowest of the NFL teams has? Is it even close?
if it is even close, then consider this theory (fact?), USA citizens are on average, way more fanatical about their sports. Odds are, that out of the same sized pool of people, more USA americans with go to an NFL game than Canadians will go to a CFL game.