Uh...a laptop for work? This is not sounding like a great vacation, Bjorn!
Anyway, thats a tough question. Lot of variablestemperature (electrons slow down when its cold), cloud cover, much more. Charging an iPod is easy; its the laptop thats a challenge. You need a mid-power charger for that, one that cranks out 14 watts or more.
Several might work. One good choice is the Brunton SolarRoll 14 ($655 retail, but you can find one on the web for $400 or so). VERY popular with outdoorspeople. It's powerful, for one thing (you can even charge a car battery). For another, as its name implies, it rolls up quite nicely and stores in a tube. When unfurled, its 17 inches wide and 57 inces long, kind of awkward, but you must be pulling a sled so it would sit nicely atop that and charge whatever needs charging.
If you can do without the laptop, then Solios Universal Solar Charger ($100) is a slick unit. Its internal battery stores energy, so you can charge it during the day then use it to power your iPod, wireless phone, etc., at night. Not enough oomph for a laptop, however. And while there ARE issues with a battery in very cold weather, there are ways around that put it in your sleeping bag, or next to your body, and warm it up.
You are a hard man, Bjorn. Hope you have a good trip. Send us a photo with your solar-charged camera and laptop while en route.