Municipal sites France - do we need to book?

mmd333

We are driving down towards the alps at the end of July and will need 1 or maybe 2 stops.  We intend to drive as far as possible until the children get restless so we dont really know how far we'll get before we decide to stop.  Is it risky at peak season
hoping to turn up at a site for 1 night, especially if its close to the main route.