6010 is not considered a filler you would wish to use for temps that low.
And while I'm not familiar with CSA requirements I doubt you are qualified without testing.
I would suggest instead of looking for exemptions look for requirements.
And I wouldn't use the term they have garanteed impact energies. What they have is tested impact energies under a specific regime. but to be honest, I would n't even consider exempting it. If your application is temps that low get rid of the 6010 and do the testing.

I was unable to find anything in the joining section (using 03 edition) specifically dealing with welding & notch toughness; however, take a look at Z662, section 5.2.2.  I think that in your case 5.2.2.2 applies and the last sentence states "... Where applicable, sutch notch toughness properties shall be proven at or below the applicable minimum design temperature."  I would also check the project specification which may address this issue... they may require procedure testing to demonstrate impact values and may even disallow the use of the E6011 if impact properties are required.  Personally, with an E6011 consumable, the potential variation in technique if I was the owner I would want to see a procedure test with impacts.  I have also never heard of exempting impact testing for PQRs if materials have guarantee minimums.

BTW don't take for granted that the material will have guaranteed CVNs.  Last year on a structural project I had a beam (customer supplied) with supposedly fabulous CVN values on paper.  When we went to do production PQRs the PQR CVNs went down to base metal microstructure issues.  The problem was contained to one side of a flange, but it does show that just because it is on paper doesn't mean there cannot be a problem.

In general, having base metal certified to a low temperature, and using consumables with a low temperature classificaiton, is no fundamental guarantee that production weld metal or HAZ will achieve corresponding properties.  Think about all the variables (formally identified or otherwise) involved and the controls necessary in order to obtain confident predictability for production (which itself is typically not tested, and why qualification and adherence to qualification parameters are necessary).

Thank you very much for all your comments.  I will ask for CVN testing in their PQR's.