It was over 20 yrs ago, so hard to tell if it is worth it today or not. I went on a day trip alone, drove there, wandered around snapping photos, ate lunch (curry wurst & fries) and was home in time for dinner.
It was about 4-5 hours on the autobahn, not too far a journey. Not sure if it is worth it from S. France though, I'd probably look for some place closer in France. I remember being impressed with the Normandy museums and Verdun, but I think the tunnels in Verdun are closed at this time of year.