You can use a couple different ways, like move direct to until you reach an area with pathfinding, or setup pathfinding nodes along the way.
Personally, I would set up multiple navpoints on the route - creating and destroying them as needed to reach the long distance. That would work for smaller local areas of movement, but not smart pathfinding over very long distances (in case a mountain is in the way, for example).
In cases like that, you can most likely set up a lower res version of your map and implement something like A* on it to move around entire “regions” of the level that are impenetrable.