As they develop, some of the chassis being developed for delivery trucks could be repurposed as a small Class C/B+ but right now most of those have a pretty limited range at freeway speeds.
A key difference is your average UPS truck spends most of it's time at relatively low speeds with lots of stop and go...that's great for electric where regenerative braking can cancel out the extra power used in acceleration and at low speed, wind resistance is minimal. At freeway speeds, wind resistance is a primary control 95% of the time.
Not only is boondocking an issue a large percentage of RV parks are pushing their electric system to the limit already (particularly on busy summer weekends when everyone is running the air/con).
Chassis prices will have to come down and charging options expand before this is a viable option. That may come as current ICE chassis are not really developed for RVs. RVs just take advantage of them.
