The concept basically is to build a smaller, temporary, relatively easy to set-up and break-down room, inside a house to have a much smaller area to keep warm, and allowing the surrounding space to act as thermal break from the outside cold.
More inside and away from outside walls and windows.
A low ceiling, and for me, I put my work table, chair and bed in the same small area.
Then heating is with an electric heater or if using central heating or something would mean channeling that in, and closing off all outputs outside of the winter room(s).
Central heating would be used outside the winter room(s) as needed to keep things from freezing, if necessary.
A business might be possible if developing specialized systems to allow consumers to do-it-self easily. I don't know if it would ever be profitable because the market is so extremely small (environmental extremists). And it is difficult because of needing to deal with many different situations, and personal preferences.