Update: 33 degrees today...drove 4 blocks to the bank. Smelled a faint whiff of gasoline while idling at the atm but then it was gone. When I got home and turned on the vents, got another stronger whiff of gas then it was gone. Even sitting and revving the engine I couldn't reproduce the smell either inside the car or standing outside.

My roommate (who is pretty car savvy) couldn't smell anything either. He thinks it could be a fuel line that is sweating intermittently. Does this sound like it could be a possible scenario? He says he'll replace the fuel filter for me. His explanation sounded like it could be right to me but I don't know cars that well