Since it's for a ratsnake I'm only worried about maintaining a single hot spot. It's on a day cycle rotator as it's a halogen bulb. Don't even need a CHE for night temps, as in their native range the temp drops into the 60s at night fairly regularly. Even with just the single bulb she'll have lots of perching options to access the heat as she pleases, as well as choose where she wants to hang out for UVB.