Got all of the hotels for next week booked, and ended up changing the route. As it turns out, we'll avoid Iowa entirely, and skate up around Chicago into Wisconsin and pass through the southern most part of Minnesota instead. It shaves about a half hour off of the drive time overall.
I actually changed the route by accident. When I first did point to point driving directions, Google had me going through Omaha. When I split up the driving with a custom map, I just went with that. When I started playing around with locales to stay in (Omaha has no decent hotels on the route, as they're all way off the route), I accidentally dragged the line up enough that it put me through Chicago and showed the shorter time and distance. Little wins like that are good.
One thought you might want to consider is what time you want to go thru Chicago. Any time I need to drive thru there, I plan the trip to get me into Downtown Chitown between midnight and 5:00 AM. Otherwise it could take 3-5 hours just to go from Gary over to Elgin.
This year on a trip up to Oshkosh, we got stuck in traffic at 1:30 AM. It wasn't too bad but still added 30 minutes to the drive. And we hit this on I-94 after we were past downtown. Good luck!