I like your idea of expanding the field, but I would propose a 6 team playoff. All the power 5 conference champs and a wild card team. The top two teams get a bye. I think this makes the regular season that much better because you can play good teams out if conference to try to earn one of the bye spots, but if it doesn’t pan out then you can still win your conference and get in. For example, this year both Ohio State and Oklahoma get in, but Oklahoma would get the bye. All 6 teams would be really good so a bye week would be HUGE and a big deal.