He will feel cold if he isn't actively basking. Reptiles don't produce body heat, they can never be warmer than their environment. I would just let him be. As long as he isn't losing weight noticeably quickly, it's just brumation.
I agree, based on the picture he looks normal. His beard is normal color & it doesn't
appear that there is swelling on his hands, feet, etc. Is his weight stable, the best that
you can determine?