In reply to andy healey:
Thanks both for the alternative facts
@Howard J - problem with Carre Neige (afaik) is that it doesn't cover you for medical, just getting you off the mountain. So if your existing policy explicitly excludes off-piste...
@Chris, that's exactly my situation.
It's like if I went on a 6 month beach holiday using my work-provided, avoiding risky things insurance policy, then went for one day of climbing and wanted to get insured. I surely wouldn't need to take out 6 months of climbing insurance?
For the record, there's only a tenner difference for this holiday so it's not a biggie, but another time it could be (see example above).