Almost ruined it for me too! Fortunately I was on the bike, not in the car. Also a quick poke around on multimap came up with a route from Leatherhead (right by J9 where it was closed, of course) towards Guildford, then up some B road at East Horsley to the A3 and a quick dart along to J10 where only a short queue to the roundabout let me onto a really
really quiet M25. Quick blast to the ton before remembering the cameras
Then I had to find a nice detour around Silverstone where the A43 was closed as well. Still, saw some nice scenery and some windy roads.