No chance on a number of fronts!
As said already, one pass will only let one car in.
Our pitch last year was around 6 metres by 6 metres - we just about got Chateau Piglet on it (9 man tent) by turning it across the pitch, short guying it and slightly invading our neighbours!.
This gave us just enough room for a seating area at the back of the pitch. We had a tree in the corner of the pitch as well to add to the amusement!
We couldn't fit the car on the pitch and were saved by the fact that the pitch opposite remained empty as it had a blooming great tree on it and the Frenchies that turned up refused to take it!
I'd flog the Houx ticket and buy one for another site but you'll still have the car problem.
If you go for Houx, it does have an electricity supply, you'll need the right connection to join to it, lots of extension lead and if you're not their early in the week you'll probably need a multi adapter as the "stack" that supplies the power will probably be full.
The cheapest way is to take an ordinary domestic fridge from the UK if you've got space for it and run it on the electricity. If you don't get on Houx or you can't guarantee power buy a gas/12v/240 - around £129 on Towsure at the moment. TBH I'd buy one of those and not bother with the electrical hook up.
Enjoy!!