Packing for Icelandand Copenhagen in early December

It is going to be cold. Just remember to factor in a wind chill factor! I was there in June and had rather cool weather then. The wind made it worse. I wore layers in June.

No Iceland experience but we were in Copenhagen the first week of February a couple of years ago. Key to clothing suitable for winter is layers starting with a good wicking synthetic or wool base layers top and bottom. No cotton. My base layers are thin. Pants should be tight wool or synthetic that will block wind. Mid layers provide insulation and outer layers wind and rain protection. In urban areas I do not wear overpants.

Boots with a thick enough sole and mid-sole are more important than thick socks. I use medium weight wool socks. If socks are too thick they can restrict blood flow if you boots are too tight. Streets of Copenhagen are kept clear so other than a snow event, slipping is not an issue. If you are in small villages with snow and ice being the usual, boot chains (e.g. Yak Tracks or Ice Trekkers) can be useful if the village is slow on snow and ice removal. This is not a usual problem in urban areas and Reykjavik has geothermal heating.

Heated pavements in Iceland:
http://www.nea.is/geothermal/direct-utilization/snow-melting/

In downtown Reykjavik, a snow-melting system has been installed under
the sidewalks and streets over an area of 50,000 m2

.

Just a note: I think you'll find that Vancouver weather is fairly warm compared to where you are going. I also see multiple activities. You'll be in the city but may also be out in the country looking for aurora. You'll need something that can handle both.

Iceland is known for some rather fantastic (and terrifying) winds. You'll need a good hooded rain coat and rain pants for your top layer.
I'd bring a puff jacket for under that, and 1-2 base layers. You'll also want pants, a shirt, and a sweater. NO COTTON. I usually travel with a set of silk long underwear and a set of synthetic. The synthetic has a T-zip top.

Waterproof shoes with a good tread are a decent solution during this time of year. Wear with 1-2 wool socks. Two thinner wool socks will wash and dry much faster than one thicker one.

I'd like to recommend the Montbell Versalite rain pants as an ultralight packable option. Only 4 oz in the storage bag, 1/2 the size of a soda can. Montbell also sells an ultralight rain jacket but I prefer my REI Kyoto for combination city/outdoors activities.

A synthetic fill jacket (Prima Loft) is a better choice than down under mixed weather conditions. It still works when wet. If it's going to be heavy rain then fleece is a better choice. I really like my Patagonia Nano-Puff jacket.

I have sensitive fingers so I usually travel with a pair of gloves under a set of mittens. I also have a tightly woven hat. Loose weave doesn't cut it in wind. I prefer beret style. YMMV. And don't forget a scarf.

Thanks, everyone.
I'm going out tomorrow to get some merino thermal long underwear.
I pretty much have everything else you have suggested.
I'm looking forward to my first visit to Scandinavian countries. (Does Iceland fall under that heading?!
I'm not sure.)

No, Iceland is not in Scandinavia, which is a geographical region consisting of Denmark, Sweden and Norway. Culturally it is part of the Nordic region ( Scandinavia + Iceland and Finland) Yes, it's a bit confusing.
My advise is to dress in layers as already mentioned. I have no experience with Iceland, but for Copenhagen I would expect temps between -5 and +5 celsius. If you only plan to visit the standard museum sights in Copenhagen, then I would not go all in on winter gear, but wear something thats suitable for both indoor and outdoor activities or something you can easily change out if if you visit museums, cafes and restaurants.

I take light long johns on my trips north of the Alps if I'll be traveling in May or September. This year I wore them in early May on a cool, extremely rainy day in Nice, of all places.

Just keep in mind that long johns are not something you can easily take off and put back on as the conditions change when you're out and about! I did find mine kept me more comfortable in the chilly rain than I would otherwise have been, since I traveled with a rather short waterproof jacket. If I had been going in and out of museums, I'm not sure what I would have done.

One reason I prefer silk underwear is because it is so fine and thin. That makes it very packable. It is also smooth and slippery so it doesn't catch on my street clothes. I can duck into a toilet, take off the silk layer, stuff it into a quart size zip lock, and then put it in my purse. I also like the Uniqlo airism tank as a light layer under my street clothes.

My biggest concern about this trip would be the aurora viewing. That's a lot of standing around, which is cold, cold, cold. Perhaps OP is going with a company that furnishes additional equipment such as a heavy parka? That would be a big help in packing lightly.

Winter trips can be deceiving. There's a huge difference in clothing needed for the following activities

• walking while ducking in and out of urban museums (light, easily removable layers - silk and light synthetics shine because they are light and not easily detectable under street clothes)
• active activities - need for wicking, quick drying clothing. (Synthetics shine in this area)
• standing activities like caroling, Christmas markets, and aurora viewing (need lots of layers with good wind protection as an outer layer. This is where Merino shines)

Layers are important for all of these, but the layers will differ based on the activity.

I take my silk long underwear on every trip I take, no matter where!
I was just in Venice and Scotland in September, and wore my long silk bottoms a few times as it was damp.
However, I think merino wool is what I will need for this upcoming trip.
Morten: I may have a few more questions about Copenhagen for you soon, if you don't mind! :)
Thanks, all, for you detailed answers.