I havent camped in the mid-west in cooler temps, but I have camped here in the northwest in 16-18 degree weather... during hunting season it gets pretty chilly in the central and eastern part of oregon.
a balmy 40-50 degrees is good atv riding weather here as the trails arent dusty.. and if we didnt camp in the cool weather here, we would only have about 5 months of camping per year, and that isnt enough. rain... sometimes its a part of the "real" camping experience...