We've settled on leaving the downstairs buffer open all night, but pulling Emily's bowl out of the bedroom and sending it downstairs. This prevents midnight snacking from waking us up.
It appears this causes certain associated problems to follow.
Specifically, as I hopped off the exercise bike in the living room this morning (yes, I actually rode it!), I saw spittle and kibble mixed in a pile by the forward leg of the bike. As usual, we can't be sure, but we think it's Emily.