75F-80F is NOT good for the BP. I've learned this because one of my snakes got RI from room temps being under 85F. Your tank should keep constant temps, so for now until you get a thermostat I recommend getting a dimmer. This will help lower the heat given from the UTH so it does not get so hot in the enclosure. If you do keep the heat source off, keep your room temps at 85F at least for now until you get something to control the heat source.