Re: camera info
Ah - how times have changed! I went with a totally manual 35mm SLR which still worked fine after many hours below -30C though the light meter usually packed up about -25 and I had to wind the film on carefully in case it cracked in the process.
As mentioned the trick with digital cameras is to have fresh batteries to hand and warm them up before use. You used to be able to get remote battery packs that plug into the camera with the battery kept warm inside your clothes connected by a wire, might be worth a google? When you get back inside after it being cold out, leave the camera in its bag for a few hours before you open it up or you get loads of condensation on it.
I have to disagree with the comment about compact cameras v SLRs. I had a quality SLR and a quality small compact. At first I used to carry the SLR most of the time and the compact all the time. Then I realised that ALL of my best pictures and the great majority of the good ones were taken with the SLR. So I then took the SLR with me everywhere and compact took up duty for party-type shots only as it was drunk-proof in operation and bounced better when dropped (care still needed though).