I've actually had success with upgrades at CDG, but what happens there seems to be totally arbitrary. The check in counters have worked best, but everything seems to depend on the agent you get, how long they've been there, what kind of meal they had the previous evening, etc. The gate agents are usually harrassed, irritable, and bombarded with requests for one thing or another. The innocent, slightly confused, "could you help me" appeal to authority seems to work best. Good luck.

PS.I'll be coming in to CDG at 10:30 from SFO on the 26th;maybe I'll see you passing on to your NC seat.