I am going to do a similar thing later in the year. I intend to go direct to Abbeville and use it as a base. There is a motel (basic but OK) and restaurant on the airfield, the landing fee is a few Euros (2.80! for a microlight). Overnight parking is free. If you want to camp next to the aircraft that is fine with them. The motel/restaurant is up to speed on the weather/aircraft US/change of plans etc and doesn't usually get stressed if you cancel or change late on the day. You will need to give 4 hours notice for customs purposes, by fax.
Rans6Andrew