Does anyone have a personal philosophy regarding the "best" time to use the downstairs shower on a Superliner sleeper (particularly on the Southwest Chief and the Empire Builder?)

On my upcoming trip, I'd prefer to avoid it when:

a) the water's ice cold.

b) the shower is a slimy, hairy mess because five people have used it immediately before me.

c) there's an impatient family of twelve waiting outside the door.

I'd imagine that mornings are Prime Time. But for all I know, "shower rush hour" could be after 10 at night because nobody wants to miss their meals or the scenery.

Has anyone noticed a general "behavioral trend" during their long distance travels?