If you can try to work nights. Work waiting tables or something like that, it will give you the ability to ski all day and you will probably make more money.
I would try to avoid ski instructing unless it is part-time. If you are full-time you will end up skiing for yourself two days a week and teaching 5, and that is not why you are there. If you think you will love teaching that is different, but don't teach full-time and think you will get to ski for yourself all day, you won't.
If you can get a job at a shop on the hill you might get three full days a week to ski with a ski break everyday, which is pretty good, but not as good as working nights.
Like I said, waiting tables at night is one of the best ways to do it. If you can get a bartending job that is great, but they are really hard to land.