IF its fresh water , and the interior has not floated away in a soup of wood chips why rebuild?
Simply power wash everything and scrub scrub scrub.
Dry with a de- humidifier and go for an adventure.
So the Alt dies , its probably a Delco car unit at $39.00 rebuilt from auto zone.
Some stuff , like a bilge pump might need replacing as a safety item , but the FW pump will be good till it finally dies.
A hand held Vhf and GPS would easily do the Loop.
Use an ice chest as you wait for the reefer to come back or need R&R.