Fongmeister mentioned:

We do. Winter is a great time to go camping. Having a Syncro helps, but
usually just means I get stuck further from help. I normally get stuck every
time I hit the snowy back roads, but it's half the fun, trying to go
somewhere that's a challenge, not the digging out part.

What I enjoy the most, is the solitude and the peace and quiet. A single
Coleman 3000 watt heater keeps us plenty warm (even with the top up). Our
down bags are only rated at 20 degrees, but again keeps us plenty warm.

Happy (Snowy) Trails,
Tim

Hmmm... where is it I can find oneofthemthar 3KW heaters.   I use an old
portable, kinda like mineself, Coleman catalytic rated at 2600BTU, generally
speaking and on a good day.  Could use a new heater.  The snuggle rug is a
12v warming blanket that runs off the auxbat found at Flying J long ago.
That and a good ol' bag will do it usually.  A sno-park pass is cheap and
the locations are pretty nice.   For shoreside, a 1200W cube heater and the
extension cord do the trick.

Only problem with unvented heaters is the condensation.  If you leave all
the windows open the condensation isn't much of a problem...