We're going to Longleat at October half term and, having read this thread, can't wait.
Been saving Tesco vouchers for our 'passports'. If anyone isn't aware, if you use them for days out (theme parks, castles etc) you get 4 times the face value. You have to trade them in for specific vouchers in advance though and can't just hand the Tesco vouchers in at the attraction. Well worth doing as it'll only cost us