I wouldn’t think twice about it. I’ve run mine for weeks when I only had 15 amp power (driveway surfing). It is a very small flame, behind a plate, behind a door— a single 30# tank will last for months.
Shut off as much
12v as you can. If your batteries drift down powering parasitic loads, the reefer will shut down. For that reason, I would not power the fan — shouldn’t need it anyway as the reefer doors will not be opening several times a day.
But I would probably chuck any dairy[emoji16]