France- The art of the possible-Logictics

Hi all.

Firstly an apology. I am sure this kind of question has been asked before. We want to go to France(Vendee) this year with our tourer(we being 2 adults + 13year old).

The thought of warm sunshine so appealing! However we are very nervous about the logistics of the journey/event. I'm less concerned about the mechanics of the drive- more so the logistics of the event. Has to be school holidays ideally we want to "take our time".. so an overnight ferry- perhaps Plymouth> 100 miles drive.. pitch for a day or so.. then reach destination 1 maybe stay for a week.. then move on for a week/10 days..southern Vendee as the max outpost maybe and then make our way back up to the port again an overnight stay to break to journey... total time 3weeks max..... is this the norm, is this what people do.. Im so nervous of missing times slots, ferry or campsite... what do people recommend?

Thanks

Typo in header.. sorry.