I can understand that the organisers may wish a break and some of the regulars may be on holiday too but I'd have thought passing trade especially in more touristy areas woud more than make up for this. Also, I'd be more inclined to leave the house on a Summer night too.

It's a while back but Llandudno worked that way. There may have been odd guest night outside of this but it only had regular (say 1 in 4) guest nights in the town's summer season. January was the difficult time when it might have been debatable whether to close or use a round the tables format rather than that club's usual set of three at the mic format for singers nights. The passing summer trade brought in the odd floor singer as well as audience.