You can search for local classifieds groups and pet sales groups. I know of a group strictly for Ontario rabbit and cavy sales, however the animals sold through that group are show/breeding stock, purebred and pedigreed, not mixed breed pet rabbits.
Kijiji, I think hoobly covers canada...., feed store flyers, local newspaper ads, yahoo groups especially for purebreds, any rabbit clubs in your area, if purebred and there's a show near enough haul them there even if they have some DQs and people may buy them as brood stock if priced right.