Before the The Witcher 3: Wild Hunt released, it was revealed that the game's map was, 3.5 times bigger than Skyrim's map. It doesn't look like The Witcher can wear the crown for having a huge map anymore, not with Xenoblade Chronicles X on the way.
According to a video from Nintendo World Report, Xenoblade Chronicles X's map is bigger than Skyrim, Fallout 4 and The Witcher 3's maps combined. Xenoblade Chronicles X will be releasing for the Wii U on December 4th in the West, after having been released since April in Japan.
The game was pretty well recieved by its audience in Japan, selling about 85,000 copies in the first week it was released. So, while we wait for out copy of the game, check out comparison of traversing Skyrim's map and Xenoblade's map.