It has been mentioned and it is what I do to my B3200. I use one of those small orange Torpedo heaters. I set it about 5 feet from the tractor, aimed at the underside from the side. It works GREAT. She fires right up with very little smoke and hardly any chugging. I keep the tractor in an unheated garage. I am not trying to warm the whole garage but heat directly to the underside of the tractor. I hold the glow plugs on for a minimum of 30 to 40 seconds.
I realize there are times we want to just go right out there and fire it up. But it is just to violent of a start up. While the Torpedo heater is warming her up, I might putz around and check the tractor over a bit, greese etc...