Don't you hate when that happens?
Had it happen to my semi-tractor ONCE! I came home for Thanksgiving one year, not knowing that the temps were going to fall so low, and filled my tanks down south. Came time to go back out and she would start but, anything over idle, and she would quit. I learned a lesson that day!
My 430 had a block heater. The glow-plugs never worked (as far as I can remember) so, when the temp dropped below ~40deg, I plugged it in. I could walk into the (detatched, unheated/uninsulated) garage on a -10deg day and feel the heat radiating off of the tractor. I never had a problem with gelled fuel.
I am also not a fan of additives. BUT...I use an old 15gal 'Blitz' fuel station to fuel my x748. My x748 does NOT have a block heater installed and, after looking at the service manual, I probably won't install one (the glow plugs work...amazingly well!) Last fall, when I topped that tank off, I added Power Service (white bottle) before I filled it and haven't had any gelled fuel yet - including going out on a -10deg day. The White bottle of Power Service is designed to keep the fuel from gelling. The Red bottle (911) is designed to thaw the fuel and get your diesel running - follow the directions on the bottle! The problem with Power Service, is that it is packaged to work with the (50/75/100gal) fuel tanks on semi-tractors... When I was out to my JD dealer last fall (after buying the Power Service) I noticed they offered an additive designed to work with our small fuel tanks. Something to keep in mind next year!