h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I actually spent a night in a snow cave and "quite comfortable" is not an expression I would expect to apply. During cold weather training with the military, I and two others dug a hole, complete with a "cold sink" on the floor and had plenty of insulation.

In summary, it was cold, wet and rained in our snow cave. Horrible drips of water came down from the roof, a form of artic chinese water torture. Although the hypothermia numbed our nerves to pain, the madness derived from the incessant dripping could not be kept out.

These techniques may insure your survival. A better tip may be to never never never leave the lodge. There's a fire, the bar is tended, your bunk and perhaps your bunk mate are warm. Watch a nature video.

No drips in my snow cave - perhaps the temperature was at that annoying point where it's still bloody cold but too close to zero to stay frozen?

In any case I agree with you - the comfort is relative - its better than being outside in the elements but not as good as a nice cosy mountain hut!

Sprout

No problems with spending the night in a snowcave beeing properly built. No problem spending two or three nights either. But with more than three nights you have to remove the ice crust that will form on the inside of the roof.
The only problem is the amount of time you need to make a good shelter to use for multiple nights. An emergency shelter you can dig relatively fast, but a large acommodotation cave will take 5 to 6 hours to make.
But once your inside its windproof, and quite cosy inside the sleeping bag. So there...

I recently spent a fairly comfortable night in a snowhole in Norway - just for 'fun'. I can recommend plenty of ground isolation and a gore-tex or similar bivvy bag. I think the whisky helped too! Secret? - dig it well, stay dry & eat plenty.