Being a knittingholic I attended the British Wool Event at the Great Yorkshire Showground Harrogate last Sunday.
I went in the motorhome of course and I wasn't the only one to do so. However I parked next to another motorhomer who had parked there overnight!! They were just a visitor to the show. They told me that overnighting was free as long as you emailed the Showground first and gained permission. Something to do with the grounds.
So I have emailed said Showground and asked for further information. Will update when I receive a reply.