I did my NR at Thruxton. They open until 8pm over winter and have full lit runway facilities etc but do charge an increased hourly rate (approx £10 ph more) to hire the aircraft. I am told this is mainly to cover the costs of paying the overtime for the fire crew to keep the field licensed!!
Well worth it though - I night flying provides for some fantastic views... You can actually see bristol and the bristol channel from FL100 over Thruxton
Steve