If it is along your way the Maquoketa Caves State Park in Iowa was a real quiet park. Electricity, no water or septic, 11 dollars a night and some great hikes and scenery......well worth the stop.......also along the way is Starved Rock State Park in Illinois.....it was quiet when we were there, but has the potential to be pretty busy. It also had some great hikes and beautiful scenery. Camp was nice.....electricity only, 25 dollars a night.
I80 Truck stop was worth the stop........largest truck stop in the world.
We stayed at the KOA in Sioux City SD......nice people, small sites, dirty.....not impressed.....45 dollars a night.
Have a safe trip.