Wot Peli said.
We used to go camping regularly with our collie/springer cross, with no real issues. She used to guard the tent if we went away to do the washing up or whatever, and severely frightened some friendly Nederlanders who wanted to give her a bone from their food, while we were down the other end of the campsite. When she was told to "guard it" she took her responsibilities very seriously. She slept on the other side of the 6 man tent from us two, and would wander over to say hello in the morning, if one of us looked at her. I do think its only workable with a well behaved dog though, the thought of camping with some of the uncontrolled idiot hounds I see about would be terrifying.
We did once go on holiday to Bala, and had to give up as it was so wet we had to take her out in the car every day with the heating on full tilt, to dry her out. That said, pretty well every time we cross the Welsh border, the heavens open.