I've owned diesels for many years now and never had a problem with fuel jelling in Indiana winters, where sometimes, it got down to 20 below zero (F) and that was the true temperature, not wind chill. My truck did not have problems.
When temps get to zero, I'll plug in the block heater, but that does not help with the diesel fuel.
There are two types of diesel fuel, the Summer Blend and the Winter Blend. In the Northern States, the fuel companies begin mixing the diesel fuel with the winter formula, and as long as you use your fuel in the season it was bought, it's never a problem jelling.
Home heating fuel uses diesel also. I understand from my mother's fuel oil man, the difference in the winter blend for home heating is the fact they add kerosene to the fuel oil (diesel) to keep it from jelling
She has an outside oil tank at her house and it's never jelled up.
So, as long as you are using the fuel you purchase in the Northern states, you will NOT have jelling problems with diesel.