Generally at Easter we look for a site with an indoor heated swimming pool so at least on the bad days (should you have any) you can still take the children swimming). The weather does not improve tremendously further south so we usually just stay north - at least you are still in france. Also - we do Dover / Calais or Dunkirk in order to avoid any bad crossings. Sites - La Bien Assize (Castles Chain) and in the Caravan Club Travel Service in Europe Book or Ferme des Aulnes (Camping Cheque Book) both are not too far from the port. Chateau Drancourt has an indoor pool but we have been before just as it has opened for Easter and the pool has not been cleaned and in use and not many of the other services are operational unlike Bien Assize which is ready for business!