I booked CMHC sites for September and for July as I got in early. I know we can book into Eastnor castle fairly easily and was about to do so just as a tester.
However, the son and his wife have just booked a site together with their daughter, husband and kids. First time for them in their new tent. So we booked in there. Just a field but with very good showers and toilets (not that we use them). Managed to book for the 18th, no hook up, but only 2 nights. £35 total. Just north of Cheltenham
John