We're seriously considering getting two cats soon. Having just recently had a cat who had the run of the house, we think we may want to confine the cats to a room at night. My 90 year-old mother lives with us and sometimes gets up during the night. I don't want her tripping over the cats in the semi-darkness or have them slip into her room when the door is open. We have a bedroom that can be "theirs". Does anyone do this? The room would have their litter box, food and water. Since that room is upstairs, would it be too confusing to have a second litter box downstairs too?