In reply to peter c:
If you have worn other Scarpa boots like Mantas or similar then in the smaller end of the sizing they seem to be pretty consistent. In the larger sizes there seems to be more variation. I had a pair that were size 40, but when I wore them out I got a size down to reduce the amount of heel lift I was getting and I'm really pleased I did. I don't find my feet get cold in the smaller ones, they are such warm boots anyway and amazingly dry! So long as you don't wear them outside, whichever retailer you go with should be able to exchange them for you if you cover the cost of postage, so all is not lost... Might be worth checking the policy on exchanges before buying though.