24 pax on a domestic.

Back in the bmi days I've been the only passenger in the business cabin on a Dublin flight on a mid-haul plane (pre-flat beds) when the business cabin was 31 comfy recliners in brown leather extending back beyond doors 2. Not sure how many were behind the curtain but wasn't that many. It was an evening flight and the lights were kept dimmed throughout while the two crew for the business cabin kept me in gin and chat right up to short finals.