Anyone know about how MTU decides on Michigan residency?

I started at MTU fall of 2014 as an out-of-state student.
As of this summer, I'm moving off campus.
I may be marrying a MI resident as well in the next few years (before/during grad school).
Anyone know how either of these would affect residency in the eyes of the uni? It'd be great to save a little on tuition, lol. (Although, I'm going to have to look into the consequences on taxes too.)

Thanks!