Me and me other half are trying to trek/climb Mercedario next Xmas. I already have loads of good stuff for winter walking and climbing, but I wonder if anyone has any first hand experience of 6,000m temperatures in the Argetine Andes. My concern is that I am loathe to buy a pair of plastic boots and was wondering if my lovely broken in B3 Scarpa Fitzroys and insulated Yeti extreme gaitors would do me OK? I've sat on a winter belay in Scotland for an hour and a half not moving, and didn't get cold feet, but then I have no experience comparing this to Andes......
