Avoiding the whole tire issue, Gowesty makes a great point about wheel
size in their write-ups.  I have had real world experience/buffoonery with
exacly what they said.
    Driving south on the Haul Road in Alaska in my 14" MXT shod Westy, on
rock completely destroyed both tires on one side of the van.  I had one
spare. I limped into Fairbanks in search of proper tires.  Their was a VW
Rialta RV with the same problem.  I called/checked every tire shop in
Alaska for proper tires.  No joy.  If I had been on 15 or 16 inch wheels I
could have purchased properly rated light truck tires at any local shop.
    If you need new tires anyway, a wheel upgrade makes a huge improvement
in performance and you ability to source proper tires locally, as well as
your choice of tires.  If you plan to adventure far and wide in you van, I
would definely think about this.  It ruined the last couple weeks of my
road-trip-of-a-lifetime.

John