I would think that the magnetic heater should do fine as long as the tractor is in a enclosed area. I would still pop the question over to Vic as he has more experience on the cold weather maintenance of tractors then I do down her in Western Washington. The coldest weather I had to start my L1801 was -5 Celsius after a heavy snow fall 3 years ago and what I did was glow plug the engine for a couple minutes then pulled out the decompression knob and got the engine to spin up until the oil light went out and then pushed in the knob and it still took a couple of cycles of glowing the engine and pulling out the decompression knob and it started and I let it sit and smoke out the garage, Have the door open when you do it.
You should be getting the manual any day now....
You should be getting the manual any day now....