We are flying from U.S. to London via Delta, then switching to British Airways on to Paris. We want to get a bottle of Vodka for our hotel room in Paris. Where should we buy it? Can we buy it at CDG after we get off the plane but before customs? Can we buy it in LHR after security and bring it to Paris? Can we buy it/order it on the BA plane - duty free? Or should we try to find a liquor store in Paris? Thanks