You're right about Missouri. Plus, it's really nice for them to play their title games at the Edward Jones Dome. I know Illinois has their football championships on Friday (Classes 1A-4A) and Saturday (Classes 5A-8A) starting at 10AM. With Tennessee going to six classes, I like your idea of having the 1A, 2A, and 3A games one weekend, and the rest of the games the following weekend.
I also like the idea of implementing a three-site rotation between Murfreesboro, Clarksville, and Cookeville. It's definitely something to explore.