We camp dry a lot, too. Your propane tank is probably 20lbs so should be plenty.
Boondocking is first about conservation so you might take a good long read in our boondocking
subforum and understand your power needs: LED bulbs, reduced furnace time, popup Gizmos
, and so on.
Most popup campers become pretty good at conserving so it will soon be second nature.
Second to power conservation is increasing your capacity with one or two deep cycle batteries, possibly using a generator or solar to charge as needed.