5 years or less? Or does he want to coach for at least 15-20 years?

If 5 or less, then you go and probably get more money in a short amount of time.

If not, then you stay at BYU, earn alot of money, build on Lavell's legacy, and create forever memories at BYU for another generation of cougar fans. Somewhere, right now, there is a 5 year old boy that in 15 years will play football at BYU with Kalani as coach and will be inspired to become a coach and become the next Kalani about 15 years after that. The only place I know of where that type of legacy can be built is at BYU.