Early heaters were corrupting the mixture by getting to Hot.... Most Now come on 25F and say on until 40F My 2013 sits during the winter months Nov 1 April 1 , outside, I generally will Use it to Pull My Snowmobile trailer to the Cabin in West Yellowstone, 2-3 Times during that Time Frame, I will start it and drive it around the block Once every 10-14 Days ( At Home) when temp and road conditions permit it. The 13 only see's the shop for maintenance and upgrades. This will be its 7th winter season outside.
I also have kept the level at 10-15% all winter, its generally around 25% during winter Months.
Josephc1 Your fine all year round even as low as 10% DS/DW both have NO solids removed when it freezes very little expansion.
I've even crawled under truck and check (DEF) tank Temp with infrared gun, I also check My fuel Tank temp... I have the auxiliary Fuel Heater in the Bypass filtration system.