Hi Dr. Rich,
Your question piqued my curiousity because I sometimes travel to that area. I think the answer, unfortunately, is not a lot--esp. if you're just going to be around the Twin Cities area and don't have much time. MN is close to, but not quite in, the regular range of most western birds. eBird coverage in MN is a bit spotty, but it did suggest Harris's Sparrow and Trumpeter Swan as a couple of the more likely possibilities in October. Less likely would be Brewer's Sparrow, Western Meadowlark, and Black-billed Magpie.
If you did some research on locations and could travel further north in the state (I'm assuming you'd arrive in the Twin Cities), you might have a shot at things like Northern Hawk Owl, Great Gray Owl, Gray Jay, Sharp-tailed Grouse, Black-backed Woodpecker, and LeConte's Sparrow. But you'd probably need to invest in a MN bird-finding guide and be willing to do a fair amount of driving to have a decent shot at those.
Best,
Jim