I haven't been up to Whistler yet, so not sure if it's there, but if there's enough snow in the village, they usually build a (free) sledding snow mound down by the Olympic rings. Bring a Crazy Carpet with you, or pick one up at the Wal-Mart in Squamish on your way up. If you want to confirm it's there, someone on the Whistler forum could tell you -

https://www.tripadvisor.ca/ShowForum..._Columbia.html

There's also a free ice rink there with skate rentals available.