Just FYI, you could do the Northwestern tour without having to go into Chicago, because you could just stop at Evanston (north of Chicago), where Northwestern is, when you drive from UW to UM. It’s a suburb (no big city driving) and there’s a parking garage where you can park when you’re touring, so he wouldn’t have to find street parking. The campus is beautiful, and you can walk by the lakeside and see some cool architecture.
But if not, the rest of your Midwestern tour sounds great! We did a similar one. Our first stop was Case Western, in Cleveland, which could be worth a look for you.