Aquitaine and I went through a bad period where I thought she might be getting dementia, even though our walker/caregiver/friend Kelly told me I was out of my freaking mind. She could not go through the night, at 3-4 am every morning for a year she woke me up with her pacing. We would take a short pee walk but that was not really her issue. Then I read on here in a thread that Denamarin might work for the problem. I reasearched it, it looked fairly benign so I added it to her daily routine. It worked. No clue at all why, didn't really care. It worked and we were back to sleeping through the night within a week or so. I will say it is not cheap at all. The price is mildly better on Amazon than at the vet, but not by much.
Also, a friend tried it with her girl for the same problem and it didn't work, so not a guarantee. Just worth a try.