I’m fairly local to Oulton park and have been in touch with a few members so far so just throwing this out there.
If anyone is coming from the m6 and plans to exit at J17 or J16 then Crewe Hall would be a great place to meet up. I have called them and suggested that this may happen and they are more than happy to accommodate members.
There will be a buffet breakfast if anybody wants it from 8am (Not cheap but a darn site cheaper and better than the burger vans at Oulton or indeed a grubby service station!). I would suggest aiming to arrive around 8:15 - 8:30 and leaving Crewe Hall no later than 9:15 for a leisurely run to Oulton for gates at 10:00
A change of heart from Oulton Park now looks like you were correct after all, not one catering van but probably two or three in addition to Chequers restaurant.