There are a lot of teams that probably could move - but ask yourself the following questions.
Is it likely the Bill's owner will pass away in the near future?
Is it likely the team will be sold once that happens?
When the Bills are sold, is it more likely that the new owner will respect history and accept the fact that his team is destined to be among the least profitable franchises?
Or will the new owner strongly consider moving to a major city with major corporate sponsorship opportunities to maximize profit on his new investment in his team?
Indeed, I have a tough time imaging a scenario where a new owner of the Bills actually KEEPS the team in Buffalo. History is nice but I don't see the other NFL owners, after dealing with all these profit sharing issues for this CBA forcing another team owner to accept a low profit situation.