I've actually done this as an experiment while on a 4WD vacation in Colorado.

Forecast was for a brief but heavy snowfall. I picked a 4WD road close to what I figured would be a plowed County road (where I could walk out if necessary) and let myself get snowed in. At 11,000'.

Now, I was WELL EQUIPPED with 3 sleeping backs, lots of longjohns and insulating clothing, food for a month, stove to melt snow for water, etc.

It was a psychological barrier that was being broken because I KNEW I had what I needed to be safe and comfortable.

There was probably 18" to 24" of snow that fell and the 2nd night it went to below zero. Then the sun came out and snow melted or consolidated and I could drive out. I never ran the Jeep for heat. Interior glass was pretty frosty from condensation from breathing.

Learned- with lots of gear for staying warm and hydrated and fed (no cooking food) it was totally a psychological exercise. Boredom set in though I had a book about Mallory and Irviine on Mt. Everest in the 1920's to read and set some REAL perspective :-)

Sleeping bags travel in the car with us - always. Insulated coveralls and more coats are added in winter.

Unimogbert