I think you got excellent advice from rc_girlca and Medusa. I live in a 2 room studio and have tried to help people by fostering till a home can be found. Unfortunately, the only plalce I have is my bathroom as well. I would just keep the door closed, the window open (with an expandable screen in place) for ventilation. I'm very fortunate in that my cats are forgiving. But there comes a time when you just have to, as a very dear friend of mine keeps telling me, learn to say, "I'd love to but I can't."

Good luck in your decision.