I usually keep colubrids with an ambient temp of 75 most of the year (80 for ambient is overkilled for kings and many other species)
During the winter the room temps is 68 which create no issue whatsoever since the hotspot is still on at 84/85, allowing proper digestion.
You are within range really as lower winter temps for colubrid is not a problem, feeding and activity may slow down a bit but chances are it won't.