I used to hang my safelight in front of the bathroom mirror. Provided the safelight is safe (colour and brightness), you may as well bounce it around the room. A small light painted room should not need more than one safelight. The real problem with small temporary spaces is that the easy ways to block light also block airflow. Make sure you ventilate the space periodically.
When I used a bathroom I had a raised bench surface that went over the bath. This made the working height much nicer. Not quite as easy to store as a simple flat surface, though.