We are picking up a car in Lille and considering drop off at CDG when we leave for home. Our flight is at 3:40pm on a Wednesday. We will likely be driving from Chantilly. When we've traveled in the U.S., we've managed big cities fine via car, as well as rental car returns to Boston Logan, Chicago O'Hare, LAX, S.F., etc. However, our practice when we've rented cars in Europe (France, SPain, Portugal, Sicily) has been to pick up and return to smaller cities or on the outskirts of town. For this trip it makes sense to return to CDG, because I can't find car rentals in or near Chantilly and there isn't a straight forward route via public transportation to CDG from Chantilly.
If I reroute my trip, by going from Moselle Valley to Verdun to Chantilly to Champagne, it does look like there is TGV from Reims directly to CDG. Right now the plan was to go from Moselle to Verdun to Reims/Champagne area to Chantilly and surrounding. It seems a bit less efficient to end in Reims vs. Chantilly, but perhaps its worth it?
I've searched the forum and the posts are at least 5 years old in regards to CDG. Looking for comments on returning to CDG. Oh, and while we've learned the road signage for France, we know very little French.