I've talked this over with Dave, and we intend to attend. Banshee Four is also interested though in his case it may depend on his girlfriend, who as a teacher would be prevented from coming along since summer break in Lower Saxony starts only a week after the end of the I&I, on the 28th. For both Banshees an additional constraint is that on the 24th we have a baptism in the family (and another one the weekend after that), though that's no dealbreaker for me; at most I might leave a day early. Ironically a possible complication time-wise is that I'm currently unemployed - I might get an immediate job offer I can't refuse within the next two months, and would be unlikely to get time off that quickly afterwards. Well, that would be tough luck.
Dave and I have of course been to Normandy, the Pas-de-Calais and Vimy Ridge before, but neither of us has been to Paris. So for that part our priority is the city itself rather than day trips into Northern France, though we would of course be along for Saumur. In fact as I've told Harold, I'm gonna hit up a former French intern at my former office who is originally from Saumur (dad was a cavalryman) and currently studying in Paris if she has any advice or might even show us around some parts if possible. Since Vimy is right on the way to Ypres, we thought it might be a stop on the transfer there.
As for Normandy, we'll definitely do Cherbourg since we failed to get there on our 2010 trip. We think however that this will be a day trip by itself (Dave also points out a historic airship base nearby), so others might spend it elsewhere, appropriate transport solutions provided. Dave will be forthcoming with a list of Normandy sites which might interest the group as a whole, even if we have seen them before ourselves. Some new ones have emerged since of course, there are some we missed earlier, and also some like Arromanches we would like to re-visit. In general we think that of the other two Normandy days, we might spend one one sites close to Caen, and one in the Omaha/Utah Beach area.