Hi!
I'm "just" the other side of the M1 down the A38 in Ripley. There is a couple of decent sites locally.
My most regular haunt is Phoenix
Link, it's a great day with an ever changing array of game types to play, not just attack&defend all day and they really use every inch of the woods.
There is also a Skirmish site nearby Ollerton and there is Matlock Combat Games which I'm yet to try.
NPF is only a short blast down the A38 as well and that is also a fantastic day out and the site actually has decent facilities (ie you'd consider poo'ing there).