I've never had any trouble with embers, we would normally build a screen between the fire and the tents but we were that shattered by time we got there we didn't bother, plus the wind was blowing away from the tents. The biggest problem I find is my kit stinking of smoke!
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.