Hmm i just had a cracking idea, shame i didnt think of it earlier, I have got a full portable beer system with cooler like exactly the same they have in the pubs, draft beer on tap!!, you can buy the barrels of beer which have about 88 pints in, amazing for parties, works out about a pound a pint and more importantly it comes out ice cold from the tap! Basically one on of these! http://www.kegworks.com/beverage-air-bm-23-keg-refrigerator-stainless-steel-418-p16393 Dammit, if i had more time i could have organised it for the main tent!