I'm trying to come up with a well engineered solution. Barriers won't cut it. This dog will chew/claw her way through anything. It took her two weeks to destroy a brand new steel mesh crate, at which point I gave up on crate training. Nothing short of a concrete bunker could contain her, and even that I'm not so sure about. It's like living with the Tasmanian Devil.
I'm thinking that elevation is the key. Perhaps something suspended from the ceiling, with one of those Kitty Habitrail tunnel things leading to it. The problem is that if it winds up being too much work for the cat, she won't bother.
Unfortunately, I also envision those elaborate squirrel-defeating bird feeders that never seem to work.
Outsmarting an animal that only thinks about one thing is harder than it sounds.