Railroads

The tunnel is vast. They walked for a day or two on end, and it showed no signs of an ending or beginning point. Although one door, like the one they busted to get in appeared in the way, they chose to avoid it.

Not only because the massive fairy is… rightfully big, but also because of the unknown factor. To run in a hostile camp of angry survivors or psychopaths is not a viable option. 'And killing these people won't wield any result or reason.'

Better avoid problems than chase after them. Without the blizzard raging above their heads, saving up food and materials for the campfire will be easier. Just walk, rest, walk more, rinse, and repeat. 

It is not a bad thing when you have to choose between glacial cold and a stroll in a tunnel. "Clear" visibility, no terrain hazard, and a friend. "From the east to the west, we walk. Our journey pious and right, in search of enlightened knowledge."