Hey OP, first of all congrats, this is an inspirational post, and most likely a post that will provide me and other a lot of help in the future.

Quick question - how is the heat insulation and retention in a shed like this? Not sure where you live, but I would be curious if this kind of shed would be "livable" with 0°C / 32°F outside temperature, with a portable (not too large) electric heater?