On the MKE-MSP, you probably won't get offered any beer or wine as the route is less than 350 miles (unless the plane came in from someplace else and was catered). I haven't seen the flight fuel boxes in a while (last time was on a JFK-SEA segment in October). Typical snack is a plastic baggie containing a small bottle of water, a small portion of Goldfish crackers and a Biscoff
If you like to eat something on the flight, pack your favorite snacks; if you want an adult beverage other than beer or wine, put some miniatures in your carry-on clear plastic baggie, and buy sodas to mix them with post security. Definitely bring your own pillow if you need one.
I've found flying to be quite nice with no one sitting next to me. Of course this will end on April 30.