The NFL has an International Series in London and Mexico City. I would expand the International map to include venues such as Tokyo, Berlin, Canada, Austrailia/New Zealand and South America.
I would also introduce the Nomad Series. Play a few games in places like Omaha, San Antonio, Portland, Norfolk, Albuquerque, Alaska, or Boise.
Each NFL franchise sacrifices one home home game to the International and Nomad series', for a total of 32 games played in non NFL venues. If security permits, play a game or two in front of the American Service Members stationed overseas