Got back about 20.00, no major problems on journey other than the rain. Only saw 1 speed trap, to wet for them? Most grief was on the north side M25 after Dartford during a huge storm, saw one open topped classic car stopped on M25 looked like it had returned from Le Mans & golf spun up enbankment on A12!
I don't know what it is like on the Sunday after the race, but there is the normal hours queue to pay at the toll booth near Rouen. You need to come of before that exit. After queue for the same toll for 2 year running and missing our ferry and having to repay for the return journey we now take an exit before that one. I am sure someone will come along and help you more.