One idea is to use infrared heat instead of heating the whole space.

But even more clever is to have the infrared heat follow you.

Super cool.

Imagine something like that on six light bulbs.  Less power, but just as much heat.   And it can heat you from all directions.  And light you from all directions.

UPDATE--I made it.  Today is spring.  I did not need to turn on the radiator once al winter long. And we had a couple of really cold nights.

It may of course become winter again in five minutes, this being New England on global weirding steroids, but I think it's safe to say I don't need fossil fuel heat in my room.

I will admit I turned the heat on one really cold night for my partner, who was leaving next morning at 4 am for a flight, when we'd stayed up too late to really have time to heat with the laptop.  

It's not a fully scientific experiment, but it's an urban experiment, and it was comfortable.  I could sleep.  Usually I haven't even needed the dinosaur laptop, just my newish mac charger (supposedly 6 watts--though I would guess it's a bit more than that, let's say 15 to be really conservative).