If it's that cold, I hope you have a tent that looks like this one:

 

What brand do you all feel is the best for this type of temp.

 

A big LOL to everyone worried about the truck taking the "cold" at 8k feet in California. With good antifreeze and a decent battery your Toyota will do just fine down to 30 or 40 below. My guess is that would be a record by a LONG way where you're going. We had a couple weeks last winter here in Denver where it didn't get above single digits and was well below zero every night. In the mountains that's like every night all winter! I was in northern Wyoming a couple of years back where my little Isuzu SUV squealed like a pig when I fired it up at 40 below - but it started no problem. I was sure glad it was a rental though! Brutal! I'd get up in the morning, go out and fire it up, then go back in and take a shower, get dressed and such. Then everyone in town just left their car running when they went for breakfast or whatever.

In response to your question about the truck being warmer than a tent that's probably a big NO. If you're using a winter tent (one with walls and roof NOT made of mesh) the tent will be much warmer. In the back of a truck you're off the ground so the cold air can circulate all around and metal conducts cold better than anything else. You'll freeze your butt off in the back of your Runner if you don't leave it running with the heat on which is usually not a good idea in itself.

With decent tires and some weight in the back you'll do fine in a few inches of snow. I used to drive a Honda CRX all winter and take it skiing, etc. all the time with zero issues. It'd go through up to 2 feet of light powder snow no problem (though of course you don't get much of the "Colorado Champagne" out there). Off road in 2+ feet of wet snow is an entirely different matter of course.....I've never been stuck worse than I've gotten trying to 4x in the Colorado mountains in the winter. Nothing like being belly down with the tires a full foot off of solid footing! Or driving up on top of a pile of crusty snow only to have it give way and have to crawl out the windows!

Chris

 

Personally I like the Rain-X stuff. Costs a few cents more but coats your windshield with Rain-X with every use which makes rain sheet off and snow slide off pretty easily too. I've tested it down to -15deg F.