There's a good reason to NOT go through ND. For starters, you're leaving from the southernmost part of MN, to the southernmost part of Montana. Going thru ND will add about 200 miles to a 1,000 mile trip. But the biggest reason is the oil boom in western ND around Williston. Lots of tanker trucks on Rt. 2 and I-94, and you'd be lucky to find a barn to overnight in and you'd pay a pretty penny for it. Oil field workers have taken over everything. From your location, I-90 is a straight shot to Livingston, MT.
North Dakota will settle down, but not for a few years. I recently read that they've found massive oil shale deposits in the Willison area in addition to the oil already found, which requires more equipment for extraction, and more years.