This may seem obvious but how will you transport your piggies from home to site. We use two cat caddies, with a fleece lining, two piggies to a caddy with usually some hay cake in. Although we have found they usually sleep while travelling. We tend to stop every hour or so when towing which allows us to give them a cuddle, some cucumber and other tidbits.   When we arrive they are usually relaxed and we get them into their cage as soon as possible before the awning goes up.