His natural body rythmns are likely telling him to stop eating and slow down for the Winter, yet you are keeping the temps up and throwing food in his face and then wondering why he isn't responding. His reaction is normal for an adult Cal.
Usually you can find a cool area on the floor somewhere to achieve temps in the low 60s. If you cannot find such an area, then I would leave the cage light off and just use a basking spot via undertank heater. If he uses the heater then fine, and if he doesn't, OK too. Let him decide. Keep the cage somewhat darkened (i.e. cover the front and sides with brown paper or other cover material.)
Brumation is natural. Temps in the 55-60 range for about 3 months is the ideal situation, but I have brumated kings at temps of 65 or so with success. Offer clean water once a week, but otherwise do not disturb.
If you are uncomfortable with trying to cool the snake, then keep him warm if you want. But don't expect him to eat for a few months.
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Mark G
Collection:
Assorted CA rosies
A few Ariz mtn kings