I have a strong feeling that one of his missions is to win the NC, then grow a huge coaching tree for all the AA coaches who want to climb the coaching ladder. He might want to become the Saban for AA coaches. Instead of an AD.CU will keep him as long as it takes for him to finish the project, and we can hope that the next challenge is satisfied by becoming an AD and mentoring coaches that provide opportunity to athletes.
Whether he views CU as the long term fit or not, I don't know. But if he wants, he can definitely do it here.