Racks don't perform well in unheated rooms - unless you're into colubrids.
My Freedom Breeders, Boaphiles and RBIs all hold relatively the same temps and humidity. The cool end of the drawer will be just tad over ambient for the room.
I don't know about ARS, but FB has changed their lid design so that you can opt between 100% perforated to little to no perforation. Again, no difference in my FB compared to my "closed" 41qt PVC racks in terms of temp and humidity.
If you need your cool end temps up around 80 degrees, you will need to keep the room over 76 degrees even with an RBI or an AP rack.