to be honest i think that really the outside temp has nothing to do with this and its leading you up the wrong path.
go back to the start.
what is going on? do you lights? do you have fuel pump priming? do you have fuel pressure? are the injectors delivering? when it cranks are u getting sufficient voltage from the battery (test it with a multimeter please, not just say that you have lights)? are you getting spark? dose the ecu have necessary power? etc etc.
start with basic checks and work your way though, and eliminate each essential system methodically.