My suggestion would be to stay off mountain passes in Colorado in November, especially if you are not experienced driving it in snow, slush, ice, etc. Winter comes very early up in there, and this sounds like a recipe for disaster, to me.
Just sayin'. Think this thru carefully.
We/I have traveled now thru 8 cold and freezing winters, getting from here to warmer climes and getting thru cold snaps in the south. We have done just fine, but there is a bit of an art to it, and a learning curve. There are some threads on this issue, if you get on the BVan forum here, which will give you lots of information.
My husband could drive anything, anywhere, and did, particularly when heading south from here in January. We never went off the road, did get stuck in snow in a campground in Missouri once, and had to wait for a thaw to get out.
Never drive on ice or black ice, of course, and if you have not driven in freezing weather, I would suggest that mountains are not the place to learn. We simply would not do it.
Boondocking in seriously cold temps is not for the faint of heart, nor for newbies, either, in my opinion. We have had temps in the teens when Boondocking, nothing froze and we lived to tell the tale, but it is not comfortable.
It is much easier and much more comfortable to plug into electric and run your furnace and a little space heater, then just keep yourself comfortable. Microfleece is a great invention.
It can be done, but it is something to do only when unavoidable, IMO. Just because your Interstate can do it doesn't mean you necessarily should.
However, if you must go and do, get on the BVan sub forum here, there is lots more info and experience shared there.