Must be:
On the beach (within 5 mins walk) (DC2)
Sheltered so the tent doesn't break (me)
Free unlimited wifi that's definitely going to work (DD1)
Nearby outdoor things to do eg canoe / kayak / bike ride / lovely walks
Nearby indoor things to do eg swimming, castles, interesting things to do, animal parks etc
We like boat trips, sailing, a farm stay would be good or one nearby to visit.
DC are 14 & 11.
Ideally within approx 4 hrs drive of Manchester but can be flexible on this.
Prepared to pay for nice facilities (maybe even a pool) but if the campsite is cheap I'll book a couple of nights at the end in a nice hotel to dry out!