We seldom leave our 2 boxers alone for more than a couple of hours if that. I've asked neighbors when we return if they heard them and the answer has always been "no". We have a Class A and will pull the drapes across the front window but leave the side windows open and some neighbors have reported seeing them sitting in the seats looking out the side windows watching the activities.
My sister's dogs will bark for a few minutes after she leaves but then settle down till she comes back and the barking commences again.
We've been camped near barkers though and it is not pleasant. One couple apparently knew their dog barks so cranked up the radio pretty high so not only did we hear the dog, we heard their radio. Thank heaven's they like the same music as I do.
Every dog is different and each situation is different. I can't promise my dogs will never bark but I guarantee I correct them each time they do bark in a campground no matter what the reason. What I don't get is why owners ignore their barking mutts and do nothing to stop them. Many times, they're the same ones that think their dog doesn't need to be tied or leashed AND also seem to think their dog's poo doesn't need to be picked up!
I see being able to bring my furkids to a campground is a privilege and not a right. I do not want to do anything or let my pups do anything that would result in the privilege to be taken away.