I think cabins are going to be difficult everywhere unless we book way ahead. If all of us are traveling, a lot of rooms will be needed. On the east side of the state are Concordia, St. John, Bruin, and Larto. Larto would be the most difficult to get enough rooms. I don't know what availability there would be on any of them.
Down your way, what kind of hotel availability is there. I know cabins would be the best, but hotels close to the lake/river would always be a possibility.