I think Portland could get up for 8 games. I'd be fine with the NFL. People think of the NFL as "big time" and Portland as not being big time because we only have one team, but there are cities in the NFL that have two pro sports teams or less:
Baltimore 2 (Ravens, Orioles)
Buffalo 2 (Bills, Sabres)
Cincinnati 2 (Bengals, Reds)
Indianapolis 2 (Colts, Pacers)
Jacksonville 1 (Jaguars)
Kansas City 2 (Chiefs, Royals)
New Orleans 2 (Saints, Hornets)
San Diego 2 (Chargers, Padres)
Seattle 2 (Seahawks, Mariners)
(Highlighted cities are smaller metro areas than Portland)
The problem, of course, is the stadium. But if there was a plan on the table, I don't see why we couldn't field a football team here. It's hard enough to get into a Ducks or Beavers game, and those teams are a couple of hours outside of the metro area.