At this point, I think it’d be tough for Iowa State or BYU to lose twice in short succession and be considered for the playoffs. Especially for BYU because at least one of those two losses would be to a relatively weak team.
I think Kansas State could win out the regular season and make it even with a loss in the CCG. Their first loss was early in the season on the road at BYU—a forgivable loss. In this scenario they’d have a recent win over Iowa State fresh in people’s minds. A loss in the CCG wouldn’t necessarily be a death blow.