Hi Lorraine,
Just come across your post and thought I'd drop you a line as I'm also heading to Frejus this summer with my family. We're staying at the La Baume site which is a Eurocamp Independent site.
Have you managed to find any stop overs yet?
We're travelling from Calais and have also added in two stops on the way down which Eurocamp helped with. The first is Chalons en Champagne, Camping Municipal and the second is St Sigolene, Camping De Vaubarlet. I know you're coming a slightly different route but one of these may possibly work. Otherwise if you're travelling via the edge of Paris I can recommend La-croix-du-vieux-Pont campsite as a lovely stopover. We've stayed here previously as it's a great family site. http://www.la-croix-du-vieux-pont.com/ Otherwise, drop Eurocamp a line, I am sure they could help with campsite suggestions.
Have a great drive and a fantastic time in Frejus. We're looking forward to it, just dreading the drive a little with two young children on board! It'll be worth it I'm sure.
All the best, Stacie