Hi, I live in north Florida. Spring, summer, and fall highs are 90's and lows are 70's. Winter is usually 55-65 with lows in the 40's. A few nights we will dip into the 20's. I will be converting my 1999 6.5 C2500 Suburban to WVO this summer, and likely will mount the tank under the vehicle. Do I need a tank heater, or would I be allright with just a heater at the filter? Thanks for the help.