In reply to GerM:
I just went through the same situation, though I live in NZ, so some options from the UK weren't available to me.
First, some general advice. One option is to get normal insurance, then use a top up for the days you might climb or ski tour. However, do NOT do this with a policy that must be home country to home country, like the BMC, the whole policy is invalid if you don't get it for the entire holiday. Instead you'll need to use one that specifically covers part trips, like World Nomads (or at least they used to.) World Nomads also has a higher over than includes mountaineering up to 6000m and off piste skiing. It doesn't soecifically cover Ice Climbing, but this may be included under mountaineering.
Someone might mention the Austrian Alpine Cub cover, but the 10,000 euro medical limit is not enough for N America.
The problem with recommending insurance is that the true test is claiming, and not many people actually have.
I didn't go with World Nomads as they got mixed reviews on some sites reviewing insurance for ease of claiming, and it was only a little bit more for me to go with the NZ Alpine club insurance, similar to BMC (only hopefully they'll actually pay out for a self called rescue!)
