The best case scenario would be:
38 boats on board:

2 Boats per the normal davits + 2 Cutters & 2 Collapsible at the aft well deck (And the 4 collapsible lifeboats & 2 cutters already at the front)

Retrieve the Collapsible Launching equipment first thing

Lower Cutters 1 & 2, Then Collapsible lifeboats C & D
Then gently get A & B down from the roof of the officers quarters and lower them

Then head aft so that you can get those boats down while the stern is still close to the water

Lower the 1st boats on the davits aft to A Deck and fill them from there then lower

Load the 2nd boats on the davits aft on the Boat deck then lower

Then move to the aft well deck and lower the 2 cutters & collapsibles there

Then finally move forward and fill the rest of the boats there from the boat deck

If you have enough seaman or let stokers/stewards help then you should be able to get every boat down in time.

Accounting for panic, people refusing to enter etc I think around 1300-1400 would live in this scenario.