Thanks for the many helpful replies. We have Taillevent booked but Gagnaire can only be done one month in advance (for lunch at least).

For our last night I have found the following Ibis hotel for 79 euros: Ibis Bastille Opera, 15 rue Breguet. Is it within a reasonable distance from the George V?

We also have the option of staying at the Travellers Paris where I have reciprocal rights through my club membership here in Auckland. Has anyone stayed there? It is located on the Champs Elysees and costs E180, so more than double. The building itself looks stunning but the rooms very plain. See http://www.thetravellersparis.com/

Many thanks for your tips.