Fernlicht goes further. At night in the countryside, you can often use it because you're literally the only car on the road.
Or maybe that's just me because when I drive long distances at night, I make it deep in the night so there's no traffic.
I've rarely driven through NRW, but at the northern edge to Niedersachen, around OsnabrÃ¼ck for example, there's definitely lights on the Autobahn. There most definitely are in Berlin, Hamburg, etc. But yes, it's mostly near and in the large cities.