If you're looking for a vehicle that you can tow with, while still getting good MPG; rarely do these two meet.
Also, since you don't plan on spending much time at each place, possibly you could change the types of campgrounds that you're looking to stay at. Several I have looked at have cabins and yurts available. Maybe those would be the types of campgrounds you could be looking for, and just use your current vehicle to haul the family and camping equipment you would need without dragging a trailer around.
Just a thought.
