The squirrels on the west coast of the United States do not hibernate, they are awake all winter even in cold places like North Idaho that get a lot of snow. I have one that comes and eats from the bird feeder. :)
Some squirrels search for a clump of leaves that never falls out of the tree and they try to build a nest. They hibernate for three weeks at a time then wake up for about a week to eat. Once they eat, they hibernate again until the winter season is over.