CFL is in it's strongest form in the past 20 years.
And no CFL market is an option for the NFL. Just won't ever happen. At all. It makes no sense for either side.
Well the NFL would make sense for Toronto, and Vancouver--because those cities have the population levels that the NFL would target. The problem is, Toronto or Vancouver likely won't support the NFL. Toronto it seems, has no passion for sports, other than the Leafs--the Argo's have never been a big draw there, and in relation to it's size--they never will be. A lot of people that live in Toronto, are transplants for jobs from other Canadian cities, and I believe this is a big factor as to why they have no passion for their football club. Also Toronto recognizes itself as an international City, and they consider the Argos a "bush league"--B team, and it's beneath them to support.
As for Vancouver-- I believe approximately 60-70 % is of Asian origin, and they don't support football. I understand that in China they really support basketball. It's funny how all these markets work. I was listening to an American sports radio program, and they were discussing the popularity of the NBA -comparing it to the NFL - and they thought the NBA had more potential, as it's such a popular sport in Asia.
In summary -- because of what I've written above, I don't think the NFL would have an interest in smaller Canadian markets--to expensive, and far to risky. It would have to be heavily subsidized, and not worth it. I can't see it happening, although I'd love the NFL to come intro Canada on a national level - "without Toronto."
Your right-unfortunately it makes "no sense" for either side-it's not a makeable deal-- "at this time."