Every campground ive been too (which is many) allow dogs. Some area's in the park may be off limits though, such as beaches, swimming area's, etc. Ive seen almost every breed at one point or another. They must be on a leash at all times, not be aggressive, and not causing others issues like constantly barking. Most people do lock them up in the RV when hot, or take them with them. However, some folks will leave them tied up or in a crate while away so others have to listen to the constant barking. Thats one of the only times ive ever had to complain to a CG host. Folks left the dog in a crate ALL DAY while on the boat and that dog would not shut up! Another time had a lady that would walk her dog every morning and let it poop on our site cause we had a big grassy area. The 3rd time i handed her my camp shovel and we had a few words. Didn't have that problem anymore. 95% of folks though are very respectful and there's no problems. But every now and then you'll get a knucklehead.
What Greene said. We have a lab we take, no problems. She is a member of the family so we treat her as such and don't leave her tied up outside either but even if we did she wouldn't bark and I won't tolerate that anyway for our sake and sake of everybody else trying to enjoy the outdoors. Nothing worse than a dog that barks constantly for no reason so as long as yours don't bark unless it has a reason, is not aggressive, and you clean up after it then it shouldn't be a problem.
unfortunately, most campgrounds have Dobermans listed as aggressive breed, and they won't allow them. Too many times we had to leave our Dobie behind.
Check ahead of time and see what breed restrictions there are.
You may be able to try some slight of hand if you have a smaller dobie, and try to pass it off as a german pinscher instead.. We were able to 'Bovine Excrement' our way past a restriction a time or two using this method.
We take our two heelers camping but they don't bark much. We were told once to put them inside bec they saw a cat and freaked out like they do at home and the manager said it was too much.
I wouldn't leave them inside unattended at all ever. Never know if the ac is gonna go out or they get out somehow. Then the campground and campers have to handle your dog loose running around while you are at the slot machines for 4 hours.