Cottonwood Falls didn't have very good lodging/camping/RV options, IMO.
I really like the lake facilities at Council Grove, and the large group campgrounds were very affordable when Marc and I organized there a couple years ago. Big B's BBQ could cater pretty well there out of Lebo as well.
Beaumont seemed to work out well, despite the lack of proximal fuel - everybody simply planned appropriately and it didn't seem to be a problem at all.