OK, finally got the 5610 delivered Friday evening. Related to this thread, I had purchased an OEM block heater because the seller said there wasn't one installed, that being weird with a piece of equipment coming out of North Dakota.
Got everything unloaded and drove it up to the house. Too late to do anything else so I was going to install the block heater as I was worried I wouldn't be able to start it in the morning, supposed to have a low of 12deg F that night.
Got the block heater and opened the engine door and son-of-a-gun if there wasn't a heater already installed! Glad of that but also ticked off that I had bought the other one. I'll return it. Anyway, plugged it in and crossed my fingers. Next morning it was 11deg F. Felt around the heater and the metal was warm. Cycled the glowplugs twice and started the engine. She was slow to fire off but she did start. That was good news but any colder and I might have problems.
I decided to try an experiment. I have a small 250 watt magnetic heater I use on the Holder tractor in the winter. I grabbed it and was easily able to slide it from below and attach it to the side of the oil pan. Plugged both up that night. Yesterday morning it was 9deg F. Went through the same start procedure and this time she popped right off. No struggling and didn't have to hold the start button any longer than when warm. The magnetic heater definitely made a difference. I think that's going to work for me. The true test will be when it gets down to -20F or so.
Right now happy with the TC. I think it will serve my needs. Installing a Quick Attach Summit 3600 snowblower tonight.