Try Duinrell. It’s not CP but it’s the same idea (cabins, awesome indoor swim centre) but it also has a theme park onsite with awesome rides (included in price).
Eurocamp and Canvas have (small, shoddy) caravans there but we hired a premium bungalow (“Duingalow”) from the site directly and it was cheap, large and in a nicer part of the site.
Located in a nice small town called Wassenar you can walk into the centre for dinner if you get fed up of self catering, and it’s a 5 minute drive to a massive sandy beach.
We went in October half term and it cost less than £1,000 for a family of 4 for four nights inlcuding eurotunnel crossings and the premium accommodation. Swimming and all the theme park rides are included. Awesome play areas too.
It’s straightforward 3.5 hour drive from Calais. We live in south London so we got up, drove to the tunnel, got into France around 10am, drove for 3 hours, stopped for lunch somewhere past Antwerp, drove for another 90 mins and were there.
Kids LOVED it and still talk about it 18 months later.
Go!!!