summer if you wanna ski more days in the season - think about it you could go in teh winter when there aren very many pro's there and you're hitting timberline and meadows's parks (which you could do at home unless your not from a good mounain) or in the summer when you wouldnt otherwise be skiing and you would have the top of the line coaches there to help you
the only drawback tho for the summer is hiking - so ideal situation.. if you can afford to go to windells in the summer, hit up a camp in whistler instead for around the same price (no hiking and a lot more fun place to be - whistler village)