Adolescence is a period when your children begin to want to fend for themselves in preparation for flying the nest. Why not ask them if they want to manage their own schedule? The only rule could be that they tell you where they are going and when, and that they are back for meal times. Naturally, this rule needs to be adapted according to the age of your children. But it can be a way to show them that you trust them. And, ski resorts are small enough that you are still likely to bump into them during the day! They are happy, you can relax, everyone wins.