I haven't rftf (sorry) but i went to a Eurocamp last year - going again this year - and can definitely say I'm taking more provisions this year!
The Euro was very much not in our favour and I spent a fortune on stuff in the supermarket.
As well as food basics (oil, salt, pepper, tea, coffee, sugar, pasta, rice, crackers etc.) I'll definitely take washing up liquid, cloths, washing up sponges, tea towel, bleach for the loo, small pack of washing powder, swim nappies, foil, cling film).
Also, depending on what time you arrive at the Campsite, there might not be anything open (when we arrived, the shop and restaurant had already closed) - so take something you can make your first meal with.