Roughing it!!!
How about driving the evening before and kipping in your car .
You say its for two people, this would best work of course if its
two blokes.
I have done it a few times. On my own I must add
Normally check the weather situation prior to setting off.
Find a quite off road spot, near Fairford, Sleeping bags/Big pillows/Blankets/Big Flask of Coffee/Tea, Some eats, and your all set.
Dont forget the Alarm Clock!!!!!
Driving late evening avoids Traffic.
Your ready then for early start , get in the queue early, then away you go for the Day.
Works for me!!
OPF