Is it likely cheaper to use a space heater than full central heating if you literally dont even use much of the space in the house that you never like go anyway?
You may not use the space, but you likely have water lines that can't handle freezing temps, and other electronics/appliances that assume living space (non condensing humidity being important)
Now, setting your thermostat lower and only heating the room you're in? Maybe. Whole house systems are damn efficient, so if you're moving around the house with the heater, that's a no go, but if you hang out in one closed door room, it's an experiment you might want to try.
Expect the bathroom to be colder than you'd like if you've spent the day in your bedroom/office.
Is there a treatment [dont mean medicine] or discussion on this topic you would recommend, thats interesting. Something, something, muscle spindle fibres?