Douw
One option is to book one of the southerly camps in the Namaqua Nat Park's Coastal region, as you might know the serious sand begins some distance north of the entrance. I see that National Parks have also taken charge of the campsites just south of the Groenrivier, one can reach these sites by gravel road.
Do you know of Rooiduin, the private camp north of Lamberts Bay? You can camp virtually on the beach, it is in a private nature reserve, with no access to any undesirable elements. The owner is Jannie Engelbrecht, he does not advertise and is a strict camp master. Lamberts Bay itself nowadays attracts the open car boot crowd.
Even the Elands Bay Caravan Park now has "permanent" residents and I will not stay there. The bar is still worth a visit, especially when the potato farmers come in for a dop.