Packing for the winter

I don't know about renting or resale, but silk underwear and spandex pants don't take up a lot of room in a bag. Put in a windbreaker, which you'll want to have anyway, then layer the silk and a sweater or two underneath it. I wouldn't try to get by with normal gloves on a ski trip, so pack your heavy gloves or mittens. Add a hat and ski socks and you're good to go. An alternative to spandex is something I did in my youth before I could afford proper ski attire. I had the cleaners apply waterproofing to my jeans which worked reasonably well.

I don't know what cities you will be going to, but I saw many people in Paris wearing down coats. You could use one coat for both skiing and keeping warm during the rest of your travels. As for bulky clothes, you can use compression bags to minimize how much room they will take in your suitcase. Silk thermals are lightweight and take up very little room.

So I'm dating myself on this, but my teen ski years were pre-ski pants boon. Tex has a good idea regarding waterproofing or think Scotchguard. We just skied in our jeans or corduroys with no treatment and long johns underneath...and we were fine, warm, and happy. Silk underwear upgrades this a bit. I think 'how cute to be skiing in the city coat'! The ski gloves and hat would be beneficial to pack. Otherwise, use what you would use in the city. (We had a family acquaintance who always skied in shorts, yes- in New England). Make do, you'll be warmer than you think, I would suggest.

You have to wear mid-calf leather boots, if you're under a certain age. I've noticed that it's, apparently, the required fashion uniform right now.

The other suggestions on light silks and other such measures might work at lower altitudes, but won't work higher up in December or January. It's just too cold and there's too much wind. For example, I prefer not to wear ski pants, but I usually as least bring them in the car. I like to wear warm-up pants over a tight pair of sweats. But up on top of the peaks at Oberstdorf and Engelberg, the icy wind cuts right through those. Not too bad as long as you're moving, but as soon as you rest on the chairlifts, the cold would start to bite. I don't know how high the pistes are at Chamonix....

"You have to wear mid-calf leather boots, if you're under a certain age. I've noticed that it's in this year. This is the required fashion uniform." Oh, yeah, I've noticed that too this year. But to answer the original question... some of the larger hotels in the Bavarian and Austrian Alps offer complete clothing and equipment rentals. I don't know about Chamonix, but perhaps you could ask your lodging? If they don't offer the service, perhaps they could recommend someone who does?

I googled Chamonix ski clothing rental and came up with this: http://www.rentski.com/english/services.asp I thought Chamonix was very Aspen like, even with those connotations, still a splendid place and very cold even in the summer. Did not see any consignment shops but plenty of pricy stores. We were happy to have longjohns in the cities in December, let alone in the Alps, so defintely take at least a pair. A friend in CO recommends Snowangel but I like silk pointelle. Bet you have some already, living in MT!
Almost everyone we saw under 40/45 yrs was wearing puffy down jackets and down sweaters for cold weather fashion.

The notion that silk is light therefore not warm is a common though mistaken belief by people who don't use silk. In truth, silk is an effective warmth layer at the usually lower skiing altitudes in the Alps as well as in the high altitude Rockies in the States. For combating wind chill, upper and lower garments specialized for that purpose are far more effective than gym clothes which are usually not mentioned in a skiing context.

I suggest calling some of the stores in Chamonix to see if they rent clothing as well. I also think you need the ski pants given the setting. This looks like a good opportunity to do some pre-trip shopping for a cute, but warm coat!