Held the last full weekend in September. Open to all Farmall and International Cubs, Cub Cadets and IH in general. The only strictly IH show in Missouri. Last show celebrated their 17th year.
I've been as a spectator. Good show. There's usually a good tractor shop-n-swap with all sort of parts for Cubs. They have a Facebook page located here:
https://www.facebook.com/cubaramatractorshow/
As far as motels, stay in Farmington. There's only one motel in Fredericktown and it's not a good experience. You probably have plenty of time to make a reservation, since the show isn't for another 9+ months.
The show has been attracting fewer people in recent years, but they're trying to get the word out for new people to come and participate. Definitely worth attending.