that's a great idea 

 someone make this and take my money! 

 I’d buy it 

 I suspect, Bitcoin mining space heaters will never actually be a thing apart from maybe in the polar circles.

If you are willing to invest in anything more expensive than a cable resistor aka electric space heater, heat pumps beat ASICs in every aspect. You get at least double the heating per Watt and the hardware is not high maintenance and obsolete after a year. So you spend less than 50% on electricity and investing the other 50% of electricity cost on buying sats beats any ASIC most of the time.