The populated area in S must be the same as USA but the low-pop area in N must be similar to what happened whit Scandinavia cowered whit wiled forest and heavy mutated beings....

http://tvtropes.org/pmwiki/pmwiki.php/TabletopGame/MutantUA?from=Main.MutantUA

to nuke an area it at least have to be a bigger town, major military target ....

People would and lived and died, just like they did in the American world.
Because people, people are everywhere.

Dogs would have been largely unaffected.
People would have survived anyway in distributed pockets.
Radiated snow would have attched itself to everything, turning them into Snow Golems that spit snowballs.

There was that one woman from Fallout 2 that apparently came from the Yukon. But still most of Canada's population lives close to the American Border. The rest of Canada is pretty empty. Second largest country on Earth and yet we only have about 33 million people.

And It better damn stay that way forever. I don't think the little forest town I'm in will become a bustling city ever but if so. I'm going further north. I plan to anyways.

well I guess the major reason for bombing the north esp port cities like Vancouver as well as potentially softening up the Anchorage front for invasion because the Chinese most likely thought that their attack was preemptive enough to avoid a nuclear holocaust. In my own personal opinion i feel that due to the strategic importance and large amounts of military and government forces present there. It was very likely some kind of vault system was implemented by either Vault-tech or one of their subsidiaries so people survived like everywhere else, but what do you think happened to the life that was adapted to the snow before the bombs fell? like bears, wolves, seals, etc....?

I am not lucky enough to live in a little forest town, but I have watched my home town quadruple it's population in just 20 years and now highrise buildings are going in, it's all the people fleeing Toronto. I moved further north but so are alot of other people. I am seriously going to look for work in Northern Ontario, Sudbury or further.

The bears probably became something like the Yao Gua(don't have the game in front of me for spell check) except with more hair, wolves probably didn't change that much since Fallout says that dogs didn't change much, seals are probably either dead from the fallout and nuclear material that wished into the ocean or mutated like the horseshoe crabs that became mirelurks except they resemble seals somewhat. But i would love to see a fallout game set in the north. I think it would be a much more pleasing landscape due to the mostly unihabited places(therefore not nuked) than the wastelands and the Mojave wasteland which looked exactly the same before the war minus the radiation.