Yes and no. My undcerstanding is that the wolves are from Canadian stock. And, it is true that mammals tend to be larger as you move further north (it is a survival strategy that conserves body heat). But, there are big white tailed deer in Canada. And there are small white tailed deer in South Texas and really small deer in the Florida Keys. In fact, there are something like 18 recognized subspecies of white tailed deer. But, they are all white tailed deer. The same goes for grey wolves. Grey wolves in their southern ranges would be expected to be smaller than the grey wolves in the northern extremes of their range. But, they are still grey wolves. They would be expected to be able to interbreed to create viable and fertile offspring. They are the same species, and have the same genes, but inbreeding and differential expression of those genes create localized subspecies that exhibit different phenotypes (outward physical manifestations of the underlying genetic code).
This is different than grey wolves v dire wolves, who are separated from each other by approximately the same amount of as humans and chimpanzees. In fact, evidence suggests that dire wolves (despite their names) are more closely related to jackals than grey wolves.
