Don't you think that would make the rest of your house really cold? If I were you, I'd keep the thermostat where it is and just add more standalone fans to the closet until you can update your ventilation. You do need to get the temps down some, but 400s aren't too terrible to cool. Department stores are selling decent fans for ridiculously low prices right now, so you could probably find a few ways to cool things down without needing to rewire your whole A/C.