Do away completely with a place location for teams. In other words, instead of San Diego Chargers and New England Patriots, just call the teams "Chargers" and "Patriots."
That way, people can root for their favorite teams regardless of location. There may be be Packers fans in Denver and Broncos fans in Green Bay, for instance.
Just have the teams play the stadiums randomly. For example, MetLife Stadium in New Jersey could host "Cardinals vs Vikings" one week and then "Falcons vs Buccaneers" another game. The Jets and Giants might actually never play one game in New Jersey because technically they are not associated with a location anymore.
In this manner, people will become fans of multiple teams and they will go watch games in their area regardless of what teams are playing.
I think this is brilliant. And it's all my idea.