@Something Fishy , what are your thoughts on spending shabbos here? Too complicated?
My first reaction is that it is indeed too complicated. There are a number of things which are a total-non issue during the week, but are deal-breakers on Shabbos. For example, you need to flip a switch to start an electric pump to flush the toilet. Perfectly fine on a Wednesday; not so much on Shabbos.
I also wonder what the halacha for carrying would be on such an island. Even if you don't plan on carrying outside, the bedrooms are technically in a different building than the rest of the house.