The Stadium is actually being built on ground near Houx Annexe. Houx Annexe will become the car park for the staduim thus no more Houx Annexe camping.
Maison Blanche is being redevoloped for the Bugatti Circuit, which will result in the campsite being much smaller. There are early reports that MB is not avaliable for the Main Race in June but the ACO are still claiming that they are using it for the Classic in July.
I have been to all three classics and have not had trouble getting tickets for any year. Last time we even got tickets for MB on the saturday when we arrived.
I am going to let the storm of the main races allocations pass by before I start worrying where to get tickets for the classic from.
Campsites for the Classic are going to be Maison Blanche and Karting Nord. But I would not hold you breath on either of these.