The North is cooler than the rest of Westeros but it is certainly not covered in snow and ice year-around. There are very few highways apart from the Kingsroad and a few other notable arteries linking major holdfasts, which slows travel to a crawl. In the south there may be a few miles between towns and villages, but in the North there may be dozens of miles between points of habitation, and large stretches of forbidding, harsh countryside with no people at all. The North is indeed vast, making up over a third of the total size of the Seven Kingdoms, stretching for over a thousand miles from the Neck to the Wall and almost as far from coast to coast.
