B_and_D -
Rather than a minivan, how about a real van? They don't all look like a plumber's work truck - some of them are really nice. Take a look at
http://roadtrek.com/ for some ideas. Roadtreks are camping vehicles in themselves, but you might be able to option out of some of the things you wouldn't need. Or, if you see something yuou like, you could just go to a Chevy dealer and take a look at an unmodified van. But the real point is, these mid-size vans, like the Chevy 2500 series, seem well set up for towing, as shown on the Specifications page. Standard tow ratings of 6000-7000 pounds is real nice.
Or maybe a full-size station wagon. There are still a few of them being made out there.
Depends on your budget, of course, and the number of people who go camping with you.
BTW, it may be urban legend, but I have heard it said that in some cars with a temperature "gauge", the sender is the same unit that is used with an idiot light. Thus it has two positions - ON and OFF, or OVERHEATED and NOT OVERHEATED. As I say, it may be just urban legend ...
Bill