We have been trying to do this for years and never quite made it. I think it depends on when you arrive. The later the better I think. When there is space in Musee they tend not to allow us to camp in the circuit.
I would be very interested to see how it can be done.
We went on the motorway to Paris then up to Rouen via Evreux. It was clear all the way until you hit Rouen and I noticed 4 patrols all stopping people. After Rouen up to Caleis it was clear.
Fully loaded my truck won't go above 70 so I' was OK.