Went outside to get the snowmobile I left on the 3038e forks and put it in the back of the truck to transport it for service. It was below 10F this AM and it was in the high teens or maybe low 20's when I went outside. Tractor wouldn't start and the battery ran out of cranking juice. Jumped it with the boat battery (it is what was handy) and it started. Ran for a few minutes and then died and would not restart.
Figured it was a fuel problem. I can see the red ring "floating" in the bowl. Looked more like a prehistoric insect trapped in amber The petcock, fuel shutoff, and the retention ring were all frozen solid so I got the salamander out and let it cook for 5 - 10 minutes. Removed the bowl and there was a solid block of ice encasing the filter screen. A few minutes in hot water in the kitchen sink took care of that. Reassembled, filled the tank (it was 1/2 full) waited for the prime and it restarted. I worked with it on and off for about 45 minutes.
As soon as I removed the fuel cap I could tell where the water came from as it was coated with frost on the inside. It snowed here the second week of November and we still have that snow and more, so it has been cold. I also filled the tank a couple weeks ago. Maybe some of that condensation was left over from the summer, but there was a lot of ice (and therefore water) in that bowl.
Drain your water separator often.
It won't keep water or condensation out of the fuel tank but it will keep it out of your engine and will allow you to start it and get it warm. As it warms it will warm the fuel in the tank and thaw/defrost the fuel in the tank.