Sounds like your snake is wanting/expecting to brumate. I've had 2 wild collected desert kings that started behaving the same way (save the regurge) this time of year. I suggest keeping the snake in a somewhat cool (60-70) and keeping it out of very bright light until the end of Feb. Don't try to feed it and don't bother it more than neccesary when changing water and doing a quick wellness check every 14 days or so.

once feb/ march rolls around, start providing some warmth and a good hot spot and after about 2 weeks offer a mouse. i'm fairly certain that it will take the mouse then.

also, i don't mean to preach, but do try and get the snake eating frozen/thawed mice. I as well as several other here have seen the damage a mouse can cause to a snake and it isn't pretty.