If you don't want to travel too far to play lots of different courses you have to go to the Hanover-Brunswick-Region (Hannover und Braunschweig).
You might see it in the map of German courses, it's in the centre of northern Germany:
Hanover has an international airport.
In the Hanover-Brunswick-Region I recommend following courses: Ilseder Hütte, Braunschweig, Salzgittersee and some other smaller courses like Peine and Hannover.
If traveling is not a problem you can reach the courses of Bremen easiliy from Hanover. And some more courses too, e.g. Dassel.
All named couses are within 100 km, much less than your trip last time.
If traveling some more km is no problem then there are some beautiful and intersting courses in the south of Germany too (e.g. Söhnstetten).