If they had any sense they would be one of the power 5 conferences. I could see them in the PAC more so than the Big 12 though.
Notre Dame and BYU have been put on notice to join a conference if they think they will have a shot at the playoffs
I think there is some religion gripes between BYU, Utah and the PAC-12. They have shown interest in the Big 12 before. ND already has its foot inside the ACC but I never liked the partnership.