Do you have a little heater in the cab?
Like Harry, I don't have a heater in my cab either. Just having the cab to block the wind, snow, and sometimes rain makes a huge difference. But there have been a few times when some heat would be nice. I remember one time a few years ago we had a big snow storm overnight and I spent close to 3 hours the next morning out snow blowing my driveway and two neighbors. Temps had dropped down below 0F that day and even with some insulated coveralls, winter boots, gloves, and hat, I was starting to get a bit chilly after a couple hours.
I've thought about hooking up something similar to this --> Cab Heater For Deere Garden Tractor
to route some heat from the engine into the cab. Although, I don't think that design (going over the grille) wouldn't work all that great on our tractors when it comes to opening the hood. So instead, I was thinking about taking a spare set of engine side tins, cutting a 2" or so diameter hole near the front of each one, welding on a 2" 90 deg elbow pointing rearward, and then running some flexible ducts from them back to the cab. I think taking the hot air right off the engine like that would lessen the chances of getting exhaust coming in too, but I would definitely add a CO monitor/alarm in the cab if I try it. And I'd have to add some sort of damper to regulate / turn off the heat so it doesn't get too hot in the cab on warmer days.
A friend of mine once tried an electric heater like this --> https://www.amazon.com/Windshield-D...bile-Windscreen/dp/B07Z9B8GNS?ref_=ast_sto_dp
in the cab of his garden tractor but quickly found out that 800 Watts was way too much for the tractor's charging system to handle.