It’s definitely possible. Get everyone out by 11am. Turn over the rooms and have check-in be at 4pm. You’re still only squeezing 1 more voyage a week in there, so it could be 165.
The challenge with that schedule is that, because of the premium nature of the experience, 5 hours is unlikely to be enough time fix damages that may occur in rooms. And, considering the limited occupancy and kid-focused nature of the experience, it’s not really viable to move a family to a different cabin if, say, decor has been torn from the walls. Allowing 24 hours of turn-over maximizes that sort of time.
I liken it to Victoria & Albert’s. The expectation is that one party will be at a table for the night. They don’t attempt to turn it over in three minutes to try and cram a second party into the evening. Rushing it increases the likelihood that something will get missed. The premium price pays for the that extra time.