In both European and American folklore, vampires are either outright nocturnal or are weak to the sun. Therefore, wouldn't it make logical sense for them to migrate with the seasons to parts of the world with long nights?
This is something I feel would be especially necessary for vampires in the folklore of northern Europe, such as the baobhan sith of the Scottish Highlands, a region that can experience as little as 6 hours per day where the sun is below the horizon.
So I guess my question is: are there any vampire folklores where they migrate with the season, and if not, why don't they?