Have you left posters with both the Wag N' Wash & The Animal Barn feed store on Portage Rd and with Owl Creek Vet Hospital?
Check with the schools about leaving posters with them as well - kids always love dogs so the more exposure the better.
Put up posters in high traffic areas such as the grocery stores, post office, insurance office, gas stations etc.
Check also with Whistler Animal Shelter - WAG, also would be good to leave posters with the various vets in Whistler.
I think a trip to Mount Currie to look for your dog might also be a good idea - it's not far away & there are always people traveling back and forth, your dog might've hitched a ride.