Actually three of the four remaining teams have the largest national followings, next to the Cowboys: Steelers, Packers and Patriots.
The Cowboys are really big with the cattle ranchers, The Steelers are favorites of the inner city rioter/looter types, and the Packers....well, that goes without saying.
4 possible SB matchups
GB vs NE
GB vs Pitts
Atl vs NE
Atl vs Pitts