We probably end up with:
4 Big 10 teams - Oregon, Ohio State, Indiana, Penn State
1 Notre Dame
1 ACC Champion
1 Big 12 Champion
1 G5 Champion
4 SEC teams if they finish at least 10-2 (Texas, Tennessee, Georgia, potentially Texas A&M or Alabama if they can come back)
A 10-3 SEC team with a loss in the SEC Championship Game would be next in line. If they still can't get to 4 SEC teams, I would expect it to be the winner of South Carolina (would be 9-3) and Clemson (would be 10-2).
Although it's still possible that Clemson could make it to the ACC Championship Game and win it if Miami loses to Syracuse next week, which means Alabama or Ole Miss could be back in the mix at 9-3. Presumably either would be ranked ahead of an 11-2 SMU team that lost the ACC Championship Game.