...and Anders calls tonight, with perfect timing. He has finished the little insulated box under our house, to house the water hardware and keep it warm over the winter.
He pointed out the need for a insulating cover for the well as it comes out of the ground (as seen here). I'll talk to Janne and Jesper to see what they say. I have plenty of wood and leftover insulation to fashion something temporary for at least this winter, I would think.
I also owe Anders' electrician for a couple of hours of extra labor to hook up all the water-heating units. That loan from Ulrika's going to come in handy!