No part of the cage should EVER get above 95. A 100 degree surface temperature is way too hot, and 110 floor temp is enough to give your BP brain damage. Saying that your Bp's haven't dug down into their substrate doesn't mean that they never will.
Pet stores keep reptiles in terrible conditions, and their employees generally know absolutely nothing about how to properly care for reptiles.
Even if your snakes did only go of feed because of the cold, having them housed together only decreases the chances of them eating. BP's don't burmate by the way.