HI, I have previously purchased the insurance on daily bases and it is possible to do that in most resorts, in the long run this is more expensive and it does not cover you while travelling. Starting from around £15 you can have insurance that will cover medical expenses, public liability, emergency and rescue etc all while skiing for 6 days plus additional two days for travel. If you have a credit card it usually has basic travel insurance attached to it, ask them if they would upgrade it to cover you while skiing - it is usually possible and very cost effective.

be safe and have FUN