If I had public service out here, I would agree with ya. I am off grid. 1200W electric heater on my solar system would be MURDER. Inverter is rated at 1500W, runs off a set of batteries 420 amp/hour. 1200 watts would be a bit over 50 amps on the batteries. 4 hours, and I am dead. if the inverter didn't expire first. Generators. My little generator would run the temporary hot water tank, barely. It did not like it. Run the larger generator, and essentially burn a quart of gasoline for a hot shower. But it worked... I finally rigged up a propane on demand water heater (cheap chinese thing, but it works!).Electric space heater with the little fan in it and I'll tell ya why.
Easy to place/hang and no risk of carbon monoxide poisoning or flames/fires.
Heats quickly with no prep time and can be put on a timer to get the shed warm before going out or turn it on from the house.
Cheap and for the amount to use it, it would cost little.
I will build a small stove out of a old propane cylinder. Maybe 12" long, vent it with a 4" pipe. There is very little fuel stored in here. I am aware of the hazards (burned up my shop 4 months ago). But that was more like several gallons of gasoline and a point of ignition...