Nordic lands were indeed ruled by vikings at some point, but vikings were not only from Norway, for example. They were like pirates but they were mainly in north europe. Vikings raided even Asia too. They were people of trading (and later raiding). I didn't see many shores in Skyrim, just the frozen ones. I saw no ships. I've seen no raids. Also, it were vikings who adopted the nordic culture (clothing, religion, etc.). In conclusion we can say that Skyrim has nords but no vikings.

Also, viking houses had no windows/holes in house walls :)