Saints expected to be very interested in former Packers/Cowboys HC Mike McCarthy [McCarthy will interview early next week]

That seems likely especially given Loomis and really most NFL GMs outside of the Jets and Raiders. As far as how long he stays, I would think he would at least stay long enough to get to 200 wins. He has 174 now so that should be in 2 or 3 years. But, maybe he would stay longer depending on where the team was.
That’s been my reasoning as to when Payton retires for good. And this applies to MM too.
200 wins AND a Super Bowl is a lock for the HOF.
You’ll get five seasons out of MM. Hopefully more if the team is winning.