[DutchmenSport]

I think, the longer one stays put in one spot, the more beneficial it would be to have the second vehicle, provided that second vehicle is a good, economical one.

However, if you travel and switch from campsite to campsite often, or travel with no schedule, or travel where the wind blows, then a second vehicle (of any kind), would be a burden more than a blessing.

Only you can weigh the costs of driving both vs just the tow vehicle only. Those costs are more than just the price of fuel, you know? That price includes the ease or difficulty of using your tow vehicle for everything.
Weigh that, opposed to a smaller run-around vehicle that will enable you to park in smaller parking spots and the maneuverability in traffic and city congestion. Plus the comfort knowing if you have mechanical problems with one vehicle you have a second vehicle to keep you mobile.