If in a lightning prone area, I would consider installing a "whole house" surge protector at the main panel like this
Leviton 120/240 volt unit. There are so many things in a house these days with electronics in them.
I think you will find that for a dedicated RV single receptacle only, the NEC does not require a ground rod at the recept. You MUST have a ground conductor (correctly sized) run along with the hot & neutral conductors. But you mention "breaker" in the MH garage so is there a 30 amp recept. only or a sub-panel?
