The dog you see in the video above is a northern Imuit Dog - not a real Dire Wolf - and could have been CGI.  Recently, WiReD wrote an article about the American Alsatian - and its claim to resemblance of the Dire Wolf in the HBO Series.

Link to article:

I found the article very poorly researched and not much attention was given to factual breeding and developement of the Dire Wolf look.  Raechel mentioned that Lois had not done any research into the evolution and developement.  Raechel did not consider the NAAC as a whole and its function. There are branches of the American Alsatian network that does research for Lois.  It was also suggested that DNA would be needed to truly develope a Dire Wolf. Many in the scientific community would agree that as far as the canid is concerned - you could claim no DNA is needed.  Just time. 

The genetic make-up of the canid is the most pliable of any domestic animal. "DOMESTICATION" is, itself, the practice of eugenics.    With time and attention, it is THEORETICALLY possible to undo the domestic "pet" canine  genetic alterations, back into its natural state. The Dire Wolf project can and will recreate a replica of the gentic structure of the extinct Dire Wolf using the very same practice of selective breeding that altered the canine to begin with. ----Shawna Davies