Hi Jim
I can't imagine living like that long term, but *temporarily*--while those 2 missing fixtures were getting installed--it might well be doable and worth it, assuming, again, it's legal to do so.
More importantly, while I get your skepticism, I don' t think you can universalize it. Having lived in developing countries and seen some pretty rough living conditions even here in the States, I don't don't find the idea of washing with a sponge all that hard to imagine. It would depend on what I'm getting for that sacrifice. We all make different trade-offs.
Not to make this into a philosophical discussion, but I don't see a big difference, qualitatively speaking, between the scenario you described and the way many people live (e.g., sharing small overcrowded apartments, being perpetually on the road and away from their families). Nor do I see a big difference between such a choice and choosing to work really long hours on the job (e.g., for a startup). The main difference here, as I see it, is that would be voluntary and temporary.
Also, I would push back on the idea that there's anything unethical about figuring out what the minimum required in this situation would be. If "occupying" a property for legal purposes is--for the sake of conversation--sleeping there 51% of the time, there's nothing wrong doing that and spending the other 49% elsewhere, whatever one's motivation.
In any case, it's a moot point since I forgot that both co-signers will have to live there. And there's no way my wife would go for this!
