In this scenario, where ISU, OU and OSU are all at 7-2, the tie breaker would be based on how the teams did against the 4th place team (most likely Texas). Therefore ISU and OU would play in the championship since OSU lost to them.If we win the next 2 and lose to WV, it would be a 3 way tie OU-OSU-ISU, and I think we are net positive against both of the Okies - which makes it guaranteed. Unfortunately Texas knows how to end a game in the clutch and KSU has more consistency, so I am not convinced we are the CCP favorite. We have 3 loseable games , OU-KSU-TX-OSU only have 2.
You're right though, there's no scenario where ISU wins the next 2 and doesn't get in.