Forget Frejus and head for Agay only about ten miles away. Camping Esterel has always been superb and especially if you have children of varying ages. Plenty of entertainment, safe, great staff, superb daily July/August entertainment and great food from the restaurant or to die for takeaway pizza cooked in front of you whilst you wait. They also have some generous sized pitches. We've had T/A with awning and 4 tents on one pitch when our kids and partners have gate crashed our hols in recent years. Castels site is not cheap, but if you want safe and plenty to entertain you and your kids few if any southern France sites will rival it! Set back from the main coast road on a hill, access and getting around also gives you a few options when the roads are busy. And the daily visits to the site fence from the wild Boar families is always a delight. Most kids and adults love the cute babies. Dog friendly as well.
Some good mountain bike trail runs around there as well if you have good legs.