Long thread, I haven't read it all. If it's been mentioned already, mine is a ditto Bring along a small nightlight. Some of those rooms are very dark, it's tricky to wake up in the middle of the night in an unfamiliar room. The problem with some of the bathrooms is the fan that comes on automatically when you leave the light on. It can be noisy.
I would have never thought of that. My 18-month-old, and in turn my wife and I, thank you for this idea .