I do think Minnesota is in a complete rebuild job so Ben Johnson will get 4 years to turn this around. And rightfully so, IMO, unless some scandal comes down the pike. But here are names I would keep in the back of my head, just in case.
I like Darian DeVries at Drake..... Good coach with limited resources
Chris Beard... I still think that situation sounded sketchy, on his fiance's end, so I might be willing to give this guy another chance. Successful at all of his stops as coach.
Jeff Linder at Wyoming - Trust me, guys,. This guy can flat out coach.. This season is an anomaly as he brought 3 guys in that he thought would be good for the program, but that ended up being malcontents from the PAC 12 that ended up quitting on him plus injuries to key players so he has had only 7 players to work with most of this season. He is a much better coach than this year's record indicates and is one of the best coaches to turn around programs in a hurry.
I think Gregg Marshall shot himself in the foot for future jobs for verbally abusing players the way he did at Wichita State. But these are names the come to mind that have experience as head coaches.