Ah well... You could wear your ski gear to school, if you dont mind getting it a little dirty. Then when you get to class say something like. I am dressing like this today to represent my passion for skiing...
I would just like to add that I had an old pair of ski pants that I wore to school on professional day. It just happened to be a very cold day and oh my god. It was so so so nice, they were super comfy and warm. I liked it so much I wore them the next day.