How do I get my GSD puppy to stop climbing gates?

It's very difficult to teach a dog to respect a baby gate and not go over it when you're not home. When she starts to mess with a gate in your presence, you can start commanding her 'No Leave It!" or something similar to start teaching her to leave the gate alone. Another trick you can try which may work is to set the baby gate on top of a couple of concrete blocks or on top of a piece of wood or even a chair so the gate is taller than the dog. It worked for my GSD (for some reason she never thought about trying to go under the gate, she totally focused on seeing if she could go over the gate!) However, I would never let a GSD pup loose in the house or even my room when I'm not home to supervise. GSD pups are like chewing machines!

Taller gate (or two gates stacked ontop eachother), a separate room with a door, or overall just more training. Try talking to an obedience trainer and teaching your dog to stay.

Or, just get used to using a crate, it's what they're there for, like you said, it isn't that long im sure your dog is perfectly content having a nap for a bit or laying with a dog bone while you're out.

You didn't say if you had tried the extra tall gates sold by drsfosterandsmith.com online. I bought one of these and it worked great for my large dogs.

Could you puppy proof a small room or spare room or laundry room, put her open crate in there along with some toys, at least one good chew (maybe an antler piece), a bowl of water and puppy pads? Then you could just close the door.