Starting by listing of participants (in no particular order)

1. Oregon
2. Ohio St
3. Penn St
4. Indiana
5. Texas
6. ACC Champ (almost certainly Miami or SMU)
7. Boise St (MWC Champ)
8. Army (AAC Champ)

That would leave 4 spots, or 3 if someone besides Texas wins the SEC.  And those spots would go to some combination of Georgia, Tennessee, Ole Miss, Alabama, Big 12 Champ, Notre Dame, ACC #2 (Miami, SMU, Clemson).

I think the Big 12 champ would still get in under that scenario, even if just as an at-large. Certainly some risk there, but I think even in that worst-case, the conference probably still makes it