The Espar is fine in that kind of cold. It's been acting up a little, but it's an issue unrelated to the cold. But in an insulated van, for sure, it'll keep me warm and toasty with no problems. Of course, at those kinds of temps, I'm not sure you'd want to shut off the engine for any length of time. A couple of years ago, though, I went to sleep and it was single digits, like 3 or 4 F above zero. I had turned the engine off just out of habit. When I woke up it was in the -15 neighborhood, but I didn't know that thanks to the Espar. Glow plugs did their deal and it started up just fine.
As for nose hairs falling off, well, a lot of stuff can gall off at those temps. The flexible hose at the fuel island is no longer flexible, so you're trying to fuel through a bent pipe that won't bend.
The soapy soap bubble bottle thing is a lot of fun. Drag the bubble wand through the air and the bubbles freeze into ice bubble instantly, and will float down to the ground and won't burst. Blow warm air into the wand to create the bubbles and the warm air quickly shrinks as it cools, creating a wrinkled skin on the ice bubbles.
At some point (depending on the humidity) the air near the ground becomes so cold that it cannot retain water vapor. The surface heat radiates up and creates a warm air "cap" that retains the cold air below. It happens a lot when the skies are clear above to create an air inversion (same thing that keeps the smog cloud hanging over a city, and fog closer to the ground, or for that matter the same thing that keeps clouds at a constant altitude instead of just floating up and away). The air near the surface causes the water vapor to freeze into an ice-fog. I saw a lot of that, where you could look straight up and see clear blue sky, but from 20 feet or so down it was nothing but ice.
Very hot water is closer to the boiling point, close to the vaporization point, so when you toss a cup full of water into the air it instantly freezes into a mist (at -30F and below). Very cold water won't freeze instantly at those temps, but will be nearly frozen as it lands, and then will freeze in a second or two after that. At -40F and below, a cup of very cold water will usually be frozen by the time it hits the ground.
I was told what happens when you urinate in -40 F temperatures, experienced from skiers and snowmobilers, no doubt, but I wasn't man enough to expose the Little General to that kind of extracurricular risk.