Accidents in "new" areas of house
Our GSD pup, Gracie, is nearly 6 months old. It had been months since she'd had an accident in the house, and Gracie was defeating the baby gates blocking off the upstairs, so we decided to take the gates down and allow her to go upstairs. She'd been upstairs before every so often, but it was still pretty much new territory for her.
Gracie seems to think of the upstairs as not part of her home or something, because she's taken to sneaking up there to pee and poop. I'm not sure why she would rather walk up a flight of stairs to relieve herself instead of just going to the back door like she's been doing for months, but that's what she's doing. And since the upstairs is the only part of my house with carpeting, it's a pain to clean. (We do use Simple Solution to clean the area, so hopefully it's taking care of any residual odor that's luring her back there.)
I can, of course, put up new, larger and more sturdy baby gates to keep her away from the upstairs, but at some point in the next decade we'll need to take the gates down, so I'd like to bite the bullet now if that's feasible.
So, what do you all recommend? Keep gates up for another 6 months? Would that likely do the trick? I can't start keeping her on a leash tied to me 24/7 again, like when she was a baby. Will she just outgrow this behavior if I keep her downstairs for some number of months? Before this I thought she was reliably house trained...