Keep looking! BPs love to hide, they like snug places like cluttered closets or up, inside dressers full of clothing- even laundry baskets- & they're far better at hiding than we are at finding. Persist & try to imagine how scared he is, & where you'd first go in his place. They often don't even travel very far- some are even right behind their cages, or within 6' of it.

I hate to say this but your dog & cat are both potential predators, even if they subdue their behavior when you're around. Pay attention to where they nose around.

Snakes can go a long time without food, but also need water, & more often- the heat & A/C in our homes is very dehydrating. I hope you find him- I know what it's like to have a snake get loose- no fun! Snakes may get into walls if there's any gaps around plumbing pipes- or under kitchen or bathroom cupboards- there's often gaps behind the doors if you look from a snake's view, from the floor- & it's very hard to get them out of some places like this, other than enticing them with food, water & their cozy familiar cage* nearby- some actually will get back in, so if you think you know where he is & it's an inaccessible place (like in the wall), try leaving it* close by & hope. Remember your snake will hide by day & be active at night- you might also stay up late with a flashlight to be on watch. Good luck!