You are have not counted the Canadian Population which is directly on Buffalo's boarder which numbers 600,000. (many of these people live closer to downtown Buffalo than people in Buffalo's American suburbs That brings Buffalo's metro up to 1.8M and the Canadian population is growing. That is 1.8 M people within a 40 minute drive to Rich satdium all within the same TV market now add in Hamilton Ontario 1 hr drive (700,000 people) and Rochester NY 1 hr drive (1.1M people) and you have 3.6 M people. That is without counting Toronto or the other 300,000 people in the southern counties of Western NY which are also within a 1.5 hour drive of the stadium.
I am not sure what you are trying to prove but Buffalo is a large market and that is why it has two big league sports teams and one of the most successful minor league baseball teams.