I suspect the NFL will just cancel the game. Next week is the last game of the season. They certainly cannot ask the two teams to play a mid-week extra game, and even if they did, since it would affect the playoff standings, they wouldn't know the AFC playoff picture until that game was done. Nor can they add a week to the regular season. The date of the Super Bowl is set in stone, and moving it would be very difficult, and, really the networks are not going to want a single stand alone game in a week 19 when they have nothing else to show in the place of all those playoff games.