Love Dougs photo
Pete, your one problem might be mildew if the cabin is kept air tight. The solution we use on the yacht is ventilation, then some ventilation and finally some ventilation, you get the picture. Doesn't matter if its cold inside providing its not the slightest bit damp and it will slowly absorb water vapour as the day and night temperatures vary.
Could be tricky to organise if that cabin is nice a waterproof, but worth thinking about and removing any moisture if possible. How about a couple of those absorbing things from e bay.
Pete