The kennel club standards are 30" for a dog and 28" for a bitch, that may seem a little low but it's still a lot of dog.
Anything over about 34" usually looks out of shape and a little freakish
That's the problem PurplePixie, people breed them for height alone and you get some really sorry looking dogs (same with wolfhounds). I've owned three and none of them were over 33". Two were in Berkshire and one was a rescue dog in Cornwall