I have done some long distances at night, across country and using a map and compass (before GPS). Most of this was after being on a Special Forces team. I have done as much as 20 miles in one period of darkness. It is possible, but it does take practice.

Doing night navigation training is useful in that it forces the individual to plan better and practice the fundamentals without relying on daytime vision. Night land nav will show a person's problems with fundamentals very quickly.