I'm a novice keeper but I do remember reading here once to put a heating pad/blanket with maybe the food of choice out and patiently wait. Also remember reading they usually don't travel far.
Sorry I'm not much help but I'm wake and tossing out my 2 cents, hopefully you find your snake soon. You already know but a reminder to secure those cats (impossible I'm sure) a little better once ya do find him.
Fingers crossed for you.