I live about 90 minutes south of Minneapolis so I do not have much info for you, but when my kids and I head up that way we stop by http://www.tcmrm.org That is a nice museum with an 2R O scale layout, next door to there is the Toy train Museum with a bunch of fun layouts, (my kids really like this one).
As far as hobby shops I have only been to two of them up there, http://choochoobobs.com/store/ and
http://www.scalemodelsupplies.com/
Choo Choo Bobs has a couple layouts, it is mostly an MTH Shop. My kids love this place, mostly because of all the Thomas wooden trains.
Scale Model supplies has a bit of everything, but no layout.
Thats about all I know about the area. Hope you find something fun to do for the night.