I'm not convinced it will drop in time - 5pm would be the very latest I'd want to leave, with 4 being better - I have crew to put ashore, and will need dinner etc - not something I want to be doing at 10pm.
If it's not dropped considerably by early / mid afternoon I think it will be a Sat morning departure - provided we arent the only ones and can get a buddy boat. After 2011 and with the new boat I'm definatly on the side of caution with this one.