Our dachshund Minna does this- in the 2 1/2 years we've had her, she's disembowled so many nice doggie beds that I finally gave up. She now sleeps under my husbands desk, in the legwell: I throw 3 soft fleece blankets into the leg well area, she tosses them over herself and burrows into them and she seems happy with this arrangement.
Paul and I call it her hovel. :blink:
So I don't really have an answer to your question: I worried about the same thing, really couldn't come up with a solution to make her stop tearing bedding up, and ended up just keeping things like that away from her.