Jesus, 6 bottles. I would definitely wait until IAD. Then you don't have to lug it around until the jetway for the CDG flight.

I would actually buy it in France and avoid the hassle. Booze is pretty cheap there; ask the Brits. I doubt duty free is that much cheaper, especially if you buy six 750 ml in a French store vs. six 1L bottles duty free. I don't think you will be judged by the size of the bottle...........

Here's a price comparison for Brits showing how cheap the booze is in a Auchan hypermarket.
http://www.day-tripper.net/priceswhisky.html

Also check:
http://www.auchandirect.fr/
Scroll to the right and select Aperetifs.

Also you do run a small risk because of customs. Obviously you are aware that you are limited to 1 liter.

Anyway, you can ask about duty free availability and pricing here. They appear to have a lot of twofer deals at IAD.

http://www.dutyfreeamericas.com/reta...fm?stateAbr=VA