Phil, I know nothing about you so please forgive me if this is all old hat to you.
Plan to take the boat apart, going from bow to stern and keel
truck, laying hands and eyes on everything including the rigging
aloft. Then once you've dealt with the obvious, take it offshore
and bounce it around for 24 hours to see what else was wrong.<G> I wouldn't be surprised if you found issues that took a week to deal with, while waiting for parts
to ship, etc.
spares, thermostat, impellers...and it might pay to inspect the fuel tank
and if there's the usual old crud in it, pull that or have someone come around to clean it. Cycle the batteries, see how much power the charging
system really will put out and hold.
After all that, go out for a few more days pushing into bad wx to get the feel for it, and to find the other gremlins. In the potential crew, too.<G>
Then stock up on film...sounds like it should be a wonderful trip!