It is a bit off-topic, but have you really seen 10-50s at campgrounds? In my experience, they have always had 14-50s at the "50 amp" level. Adapters I've significantly used are 14-50, TT-30, 5-20, and 5-15. Though if need be, I'm prepared for 14-30, L14-30, 10-30, and 6-15.
Back on topic: I...