I think Frost has, after this year, a minimum of 3-5 years. The admin and boosters have seen what happens with a constant carousel of coaching changes.
It is a risk, of course, but I don't see how it is a bigger risk than changing staffs every 3-4 years.
It took Tom Osborne nearly 2 decades to win his first MNC, though he was generally in the Top 10 every year. With what Frost inherited, I think everyone is on board with a very long leash and a very long recovery time.
I think more teams will adopt this idea/model as well, as time passes. Look at Texas, Tennessee, FSU, even Miami and LSU (defending champs) and you can see a pattern emerging. Changing staff too often is no good. Sometimes a team hits on the right guy and catches fire immediately, but that is proving to be ever more rare.
I hope that the general view becomes a longer term for coaches. That would also provide assurance that that 'hot new G5 coach' is actually the real deal. So many of those guys land a stacked team and have a great year or two. Then they are grabbed with huge money, by an impatient school/boosters and simply fail.
Finally, I wonder what Bama does when Nick retires in the next few years. Not sure why he is still coaching, really. Guy has to be worth a hundred million or more by now. I'd be on a beach in Italy, or wherever, or just hanging out with family.