Mankato is the only public program in the state that could realistically go D1/FCS. But they'd have to get a big infusion of cash, and probably a revamped stadium. The MnSCU system has been bleeding money for a while now - that money won't come from the state.
It's the fourth largest system of higher learning in the country (and remember, that's separate from the U of M system), and we're 22nd in population. I don't know how long that can be sustainable.
Enrollment is dropping at every one of the state universities with the exception of Mankato, which has by far the nicest campus and best college town setting. St. Cloud is an absolute dump of a city, as is Moorhead (though Fargo is nice). Full disclosure, I graduated from MSU-Moorhead. Enrollment is quite literally half of what it was when I went there, and I fear that if they decide to close one of the universities, it will be Moorhead. It's a horrible town with awful weather in a market with two more notable colleges.