If I ever moved back to the arctic regions like N Wis where I came from, I wouldn't even think of one tank system, like I run around on down here south of Miami. I would have two tank system with heat starting with fuel tank pickup to HoH, less apt to leak into coolant versus HiH. Flat plate heat exchanger, more plates the better before going to heated fuel filter, everything well insulated. Injection line heaters a must, block heaters, I like the kind that circulates water versus the freeze plug or oil dipstick type, I might even have a heating pad on oil pan. More heat the better. I might even have a heat exchanger on return line to tank.