You failed to mention the age of the RV or if you did I missed it.
Trailers, if you incrase the wheel size it will generally increase tire life and raise the hitch a bit, (this (hitch) may or may not be a plus) It will also pull easier.
Motor homes.. It may roll a bit easier, but... You won't gain power.. MPH may or may not be affected... You will need to re-calibrate the speedometer.
Generally, a larger tire can handle a slightly higher load.. I increased tire size on both of my tires (Cost way less to do that back then).
