Cold Enough to Freeze Tar Sands?

I have no idea at what temperature tar sands freezes, or least becomes so frost bound that it approximates rock, but one would think -40 F or so would at least get you near a point of nascent semi-solidity. Here is the current temperate gradient in the U.S. and parts of Canada. Check that little nub of dark purple sneaking in from the Edmonton area — you’re looking at -40F or so, the temperature at which Celsius and Fahrenheit are the same face-freezing pain. (To add insult to deep-tissue injury, the current wind chill in the area takes things all the way down to -45 or so.)