Can you adjust your plan by an hour or two? Stop in Hannibal or Springfield. That section of highway is rural, there are really no resort destinations, and it is not that easy finding just a hotel room. But Hannibal and Springfield are only 90 minutes apart, and at both ends you have choices.
There are RV parks in both Hannibal (I like the one at Mark Twain Cave) and Springfield. The KOA in Springfield is a chore to get to, but there are other options closer to an Interstate like Double J down on I-55.
Enroute I find Pine Lakes Resort near Pittfield. Off your route, I find a campground in Quincy, and there is RV parking at the marina in Louisiana, Missouri. Is Jacksonville a destination for your trip? Closest RV parks will be in Springfield area.
Tom Test
Itasca Spirit 29B