Okay, looks like it's grid heater relay related then.
Just unhook the positive cable, at the battery, that feeds the relay and zip tie it to the coolant reservoir. Done.
Some of them can set a code, but generally it doesn't happen if you just start the engine without waiting for the heating cycle to finish.
If you have the fancy push start button, push it twice to make the engine start instantly.
Will your pickup still start in Florida? Probably. I disconnected the grid heater on mine several years ago, it starts right up, and still haven't got a single code. Of course, so far it hasn't been at below -10.