The Alaskan wolf is a valid subspecies, and it averages about 90 lbs. There is no Russian wolf. The wolf in Russia is classified as Eurasian wolf. Eurasian wolves are widespread, found all over Asia and Europe. It averages about 90 lbs as well, so there is not much difference in average weight between them. Some Alaskan wolves can reach a maximum of 120 lbs, and indeed some Eurasian wolves can reach a maximum of 150-176 lbs.
In general, wolves are larger in cold regions than in warmer ones. The Mexican wolf, a subspecies found in the SE United States and Mexico, is much smaller than the Alaskan wolf. The reason is climate. According to Bergmann's rule, populations of the same species or closely related species of mammals tend to be larger in colder climates than in warm climates. The reason is that mammals generate body heat internally. Larger mammals have less body surface per cubic feet of volume, and therefore they lose heat less easily to the environment, since heat gain or loss is proportional to surface area. In cold regions, it benefits a large mammal because it can stay warm in a cold climate. In a warm climate however, not losing body heat easily can be a disadvantage, because it may lead to overheating and eventually death due to heat stroke. Since wolves are active animals and they run long distances, they generate a lot of body heat through exercising. In a warm climate, that extra body heat can lead to a heat stroke. If some Eurasian wolves in Russia are larger, then it may be because they live in a colder region than the Alaskan wolves. If some populations of Alaskan wolves are larger than other populations in a different area, it is because they live in a colder region as well.