BPs are fairly hardy. I told a story on this forum about a guy that stands outside the local supermarket with his 2 BPs in 40 degs. and he houses them in a 60 deg basement with just a heat lamp.
Minimum, providing heat the old school way with your heat lamp will do. Its not ideal and it drys up your humidity. I do not recommend this though .
I know old schoolers that Heat lamp, water bowl and throw a mouse in every 10 days and they'll be fine philosophy. And theyre bps are 20 yrs old.
That being said i'm on the other end where i actually measure the snakes body temp in addition to they're hot spot with a temp gun on a regular basis.