I guess the only other option would be to sell and replace the washtub every time you use it, which would be a pain. Hopefully that's something they will address long-term. The moodlet makes me think otherwise, but I can't imagine the thought process for NOT making the washtub and clothes line off-the-grid friendly.
Of course, if it were me making the lot trait, I would also have (a) made baths possible instead of showers, because they waste less water, (b) I would definitely have added a composting toilet, and (c) adding a functioning well would make a lot of sense, too. Or at least a water pump, which I seem to recall having in TS2 (although I suppose that might have been a mod).
I was planning to use this trait for a few of my existing households. But as it is, I will probably not use the trait, and just continue to act as though I have it, in the way that makes most sense to me.