We camped with our TT at Machrananish CP one year and it was a bit blowy. When we went for a run the next day the Warden said not to worry about the wind because if the TT did take off, we would find it on Jurra, an island 36 miles away.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.