When I saw the video, I have a new appreciation for the probability of Fort de Seclin being the right place. It could well be that place, as few places in France are a permanent and living museum. I think here are some great ideas for tasks:
1. Dressing up as soldiers and marching (playing the British, French or German soldiers does not look difficult and I think the probability of another Andrew/Dan marching trials/tribulations is low)
2. Find an object in that museum (I am recalling Amazing Race Asia 3 - the Miniatures Museum in Taipei)
3. Dig trenches
I am honoring your find with a map of the south side of the greater Lille area(see lowest pane) showing Seclin about 10 miles south of the center of Lille, just west of Route National E17/A1. Look to the left of the circled H. That is maybe a 20 minute drive from the train station to Seclin. With left-hand drive like in the U.S. and signage that is eminently readable there is no reason why AR16 teams could not go to self-drive vehicles which they then take on to Charles de Gaulle airport. Map of Area near Seclin France in bottom pane
I would also like to furnish directions from Seclin to CDG airport, which is 16 miles northeast of the center of Paris. It is quite simple:
1. Get on the A1 toll road south to Paris for approximately 175 km. Take the exit 6-Roissy-en-France.
2. Do a zig-zag left/right/left/left/right/right/left/right for the next 8 km.