Hang on to him. I, too, live in a one-bedroom apartment and I had a calico at one time (also used to be owned by one of my former bosses) for about four months. Was declawed and had to stay indoors but had the itch to go outside. One night, she darted out of the door and into the field across the street from the parking lot, never to be seen or heard from again.
I still miss her.