My SIL's cocker spaniel has it, took a while to get the management right but he does well now on meds. They used to have to hide all water and keep him on a lead to stop him running off to drink the puddles but I think they can leave water down now and he is happily offlead again.
My dog has all the symptoms she has me up every night several times for the loo she will also wake me up if she runs out of water.
Had all the tests but they were inconclusive. They said she may have the start of it & we have to have her retested in 6 months to see if they get a definite diagnosis . the water deprivation test I think is a bit hit or miss as she hardly had a drink at the vets but she wanders off looking for water at home & on walks.
she can also just stop out walking & then she just tatters along