I've probably seen a zillion vacation possibilities in Missouri and Illinois so it's frankly kind of hard to impress me. This new Mt. Sterling place managed to do the impossible mainly because it has a very sweet private lake.
There's nothing quite like falling asleep when you have the Mississippi River nearby. If that's also on your list of "things you'd like to experience on a getaway", I found a place in Hamilton, Illinois that offers that and also an orchard view.
I don't know about you, but when I think of I-70, I don't think of relaxing. However, there is one tiny house cabin that's hidden in a cove just off the interstate that does appear to offer a lot of relaxation options.