I had emailed the hotel on the day of supposed checkin, to let them know I wouldn't be there until 5am the next morning (I'd also put that in the booking notes, but they don't always get read...), and everything was waiting for me at 6am. No comments on the 11pm checkout the next day about an early departure, they seemed to think that was perfectly normal.

And, at some point in the last 24 hours, the stay posted as 3 qualifying nights