We have a 28 footer. Himself is mostly full time liveaboard. I come and go from the house. In five months we have worked out a few things here. As far as the butter issue goes we have a butter bell. You put water in the bottom of the base and turn the bell into the base so that the water is displaced up over the rim of the bell. The water keeps the butter sealed from outside molds and keeps it cooler than the ambient air. We stow it, along with the cheese and produce in an icebox, with no ice, that stays relatively cool. The butter keeps well for a week or more so long as you NEVER contaminate it.