DH and I have just returned from a camping holiday in Dorset where we stayed on a farm with a very well organised camping and caravanning site. There is a beautiful Georgian farmhouse next door with, I think, 10 bedrooms, that could be rented. The farm shop right next door was very well stocked, including alcohol (!!!), there was a children's play area a 2 minute walk away and farm animals to see, plus access to the site burger bar, hog roast and oven fired pizza vans on different evenings, all reasonably costed. The site is a five minute walk away from a steam railway - first stop Corfe Castle (National Trust owned) - another good family visit and we were 15 - twenty minutes away from good beaches and seaside towns with the usual amusements, cafes etc. We were also given really good beach recommendations along the Jurassic coastline where families could go fossil hunting or swim in protected spaces. AND we were quite near a Swannery (fantastic day out) .
We said at the time we would love to bring the family there in years to come - all that was missing this time was a grandchild to spoil .
I sound like an advert don't I - PM me f you want more details