Never heard of them going off food during winter. Mine eats like a horse 24/7 if i let her.

And you need to give them something to feel secure. Sure they will hide. Mine digs around her aspen all the time and my other snakes will use hides. But they dont stay hidden 24/7. At night, all of my snakes are out and about and most of the time during the day, i can easily spot them sitting half in a hide or in the case of my dumerils, she will usually not even be buried. She either sits in a hide or behind the hide curled up on the flexwatt. Sometimes when its close to dinner day, i catch her sitting at the front of the cage with her head on the litter dam like she's waiting for the rat good.

But anyways, give your snake stuff to make it feel secure and it will probably eat, assuming it was eating in the beginning. Some dumerils can be problem feeders.