If you have 4 undefeated teams from Power 5 conferences, then those 4 teams are your playoffs. Period. Sorry. If you want arguments, you'll get them if you have 5 undefeated teams.
As of now, there are 4 undefeated teams, though Georgia and FSU are in close games. Don't care that Washington almost lost, they didn't lose.
If Georgia loses, things get crazy. Then I think it's very likely that the Georgia-Alabama team gets in. If Georgia and Florida State lose, then OSU is in. Michigan still has to beat Iowa and Washington has a very tough game against Oregon. There is the possibility, though slim, we end up with NO undefeated teams after championship week.
The 12 team playoff will settle much nonsense, but teams 13 & 14 will complain.
Michigan has to win it all this year - right now - so we can experience the glory because if that happens, the University of Vacated is going to get another title, but nobody cares about the past. The NCAA is going to absolutely hammer Michigan next year.