Well it's cold. I'm not going to lie, there are points where you are colder than Cruella de Vil's heart and you want nothing more than 101 Dalmatians to snuggle up around you in a massive puppy duvet. (Canooie sat on my lap did help a little)
Heating
So getting the heater on is the main priority. Once you are generating head, insulation is key. We used 25mm celotex all around our van, sometimes doubling it up to give extra protection against your precious heat escaping. Take note and insulate the floor. Wind rushing under your van will wick away that heat as well.
Research well on the system you want to take... Burning propane in any way will generate a lot of water, hot water, that condenses on cold surfaces, ie metal vans! Wood burning stoves are hot, really really hot! and require labour intensive fuel, ie wood. Diesel heaters use 12 volt electricity to initially heat it's glow plug. Factor this in to your power generation. (more later)
Even with heating expect the cold. We regularly woke up to -6 Degrees C INSIDE the van. It took our Diesel Eberspacher D2 30 minutes to get the van up to a comfortable 12 Degrees.
We also partitioned the van, sectioning the driving part from the living part using A LOT of blankets. This in effect gave us a 'fridge' like climate in the driving bay where we stored our perishable food.
Water
Some ski resorts will have an established 'Aire de Camping-Car' which may have services. Sometimes these are paid for, or even provided free. Enquire with the resort you are headed to.
If you have a van with pipes running under, or even through your van, take in to account these WILL freeze unless you lag them well. Temperatures got to -25 degrees C on our van season, and we had a relatively warm season!
Cooking
Everyone cooks on gas. Bottles are readily available in the alps as there is no 'running gas' up in the mountains. The petrol stations have huge areas for all types. Take note that Butane will freeze in the winter and you wont be able to cook, so get Propane.
To cut down costs we purchased a Gaslow re-fillable gas bottle system. Whilst pricey to start with it soon pays for itself as it costs just 7 Euros to fill up at an LPG petrol pump, instead of the 20 - 30 Euro bottle exchange. If you are going to be in your van for a long time, I'd suggest looking in to it. Remember to buy the Euro converters for the filling point.
I'd suggest grouping together as vans when cooking. It's much nicer to eat communally, and this spreads the load between hobs. We regularly divvied out the individual components of that evenings meals between vans before coming together and sharing the food with a few beers and stories of peoples bails, sketchy avalanche moments and so-and-so having to walk for 50 minutes out of the powder.
Power
Power
From these batteries we powered a string of LED lights, the Diesel heater, water pump for the sink and a few 12 volt cigarette and 5 volt USB outlets for charging laptops and mobile phones.
We struggled with electrical energy. The diesel heater would draw a lot of energy when it first started. This scared us and we would leave the heater for a bit and turn it off. We learnt that this was not the way to play the game. Instead, leaving the heater on, meant it soon had enough heat in it to perpetuate the diesel part of the heating and the current draw would die off to a very small amount.
Charging things when you can away from the van helped a lot. There would regularly be two or three rucksacks with laptops in sat next to a power outlet in the pub. As long as you are buying beer, this should be fine, do it!
The sun in the alps during winter can pass very low in the sky. To get optimum power generation we had the panels tilted towards the suns direction via the use of some simple tilting mounts. Just remember to put them down again if you are going to move the van!
Obviously when you get that huge dump of snow at night and wake up to a blue bird day you'll be wanting to throw your gear on and get on the hill. Grab a broom and brush those panels down. The sun wont penetrate the snow at all, and you'll need that potential energy later!
Clothing
Hats are also your friend. You'll soon find yourself with permanent hat hair... but no one can see as you've always got your hat on!
Wees and Poos
Cassette toilet liquid was fairly difficult to find in the Alps for some reason, so maybe stock up when you do find some. With the cold temperatures we had no issue with smells. Having said that we used it mainly for just Wees unless it was an emergency.
Once you live in a van, whether in the alps or anywhere else, you soon get in to check with your movements. Everyone in the van park would subconsciously have a little 'Do I need it?' mental check before leaving a restaurant, pub, chalet etc.
Personally I found that I was ready to go each morning after boiling the kettle and walking up to the tourist office with a coffee. (usually in my PJs to the amusement of some tourists)
Disposal of the cassette was down a man hole cover the resort had lifted for us. Again other resorts may have a more established van park and supply a proper waste pit, maybe even a drive over one for the bigger vans.
Showering
Getting ad hoc work in the winter season is especially easy as you are living in your own accommodation, are available short notice, and are pretty reliable compared to flippant seasonnaires working they're nuts off! 'A quick shower' should always be appended when negotiating a wage. Wake up early, shovel snow for a couple of hours, quick shower, then hit the slopes. Those 2 hours of work should pay for lunch or a night in the bar!
We soon discovered that the larger complex's on resort have very pleasant spa facilities. Now I'm not condoning the unsolicited use of these facilities in any way.... but I did. A confident demeanor, generally clean atire and a a little 'Bon Soiree' to the concierge on the way in usually resulted in a wave back and an hour long soak in a jacuzzi. Quite how they didn't recognise me after a month of nearly daily use... I'll never know.
Condensation
If it's a sunny day in the Alps (of which there are many!) open your van up, give it a good airing, try and change the air in your van as much as possible. At night, when its freezing, or when its snowing, this is obviously not possible. But good air exchanges will keep your van moisture, and mould free.
We installed a roof vent in to our van and this was cracked open a little most of the time, allowing hot rising, moisture laden air, out in to the open and pulling fresher are in through door seals and vents lower down in the van. A constant stream of ventilation. At the end of the day its managing to get a happy medium between good air exchange and staying warm. A fine art!