I'm not sure about pulling a camper to Iowa in December or how far you want to drive to Desmoines.
Rock Creek near Kellogg Iowa is open year round. I doubt the roads are plowed. No water or dump station will be open but they do have outhouse there.
Really will be a gamble for conditions in December. I would not advise it.
2016 Grey Wolf 26RR
2016 chevy Silverado