I'd suggest you throw in the towel on planning to spend much time in Wisconsin on Monday and just get in the car and hightail it for Chicago as early as you're comfortable getting up.
I did a quick check just now and lots of things here will be open - Art Institute and Museum of Science and Industry, for example, are both open, and the Architectural Foundation boat tours will be operating (and with a fair amount of availability through midday.) The Michigan Avenue stores will be open, so there's lots to do. Restaurants should be open. Even with MD traffic, I can't imagine the trip out to MDW would take more the 45 minutes or so, and from the Museum of S&I you can just head straight out 55th/Garfield and be there in no time.