After I finished debugging the prototype, it required literally zero maintenance throughout the winter. Actually we were not living at the house at all, contractors doing remodelling work were living there instead. I installed a LCD screen with basic temperature controls and they had no problem with it whatsoever.

Doing this project from start to finish took me 2 or 3 months on and off, mostly during the weekends.

Doing it right yourself is the exact solution I arrived at myself :) I was shocked to discover how low the average technical level of local contractors is. I was super lucky to find a highly professional guy to overhaul the pipework, but anything more complicated I had to study on my own. Luckily, there is a ton of youtube videos, so the only thing you actually need is time.