Have you seen the machinery they use to mine the stuff? It is massive, frost won't stop them. Also, its bitumen soaked so it never really gets too hard. Alot of the oil sands are just surface mined, but they also use pump jacks and inject steam into the ground to loosen the material so it can be pumped. That is the reason they use 1 barrel of oil to get 1.2 barrels out of the ground and the reason they are contemplating building a nuclear reactor, for excess energy required to force this tar to the surface.