Depends which type of wracks, Fully enclosed PVC racks can be in little bit colder rooms, Vs Open Air wood/pvc/Ars style racks. I keep my snakes in a 77+/- room and have been fine (with open air) with a hot spot of 88.

With enclosed racks i was able to keep them in basement at 70-73ish in the basement with proper temps, But when switching to open air needed to give them a warmer ambient.