We've been RV'ing for years and have always carried a variety of adapters. 30>50, 30>15, 50>30 etc. That way no matter what service is available, I can always "plug in".
Just remember that it is better to go up then down. ie: camper is 30a but you are using the 50a service. The 50a service will provide all the juice your RV needs. If you go the other way, camper is 30a but you plug into a 15a service you probably won't be able to use the AC
AND the Micro at the same time. Just not enough power available that way.
I hate to sound like a sales pitch here, but I would also highly recommend getting an RV surge protector.
http://www.campingworld.com/category...-protectors/98
One of these saved me from a bad power surge recently. Blew out the surge guard, but the RV was intact. I'll never hook to a campsite post without one now.