maybe he will just think it's summer? seriously, I don't know. But, it doesn't seem like it'd be that bad to me, could be wrong though.
Before we had Sienna's light on a timer we'd just turn it off when we went to bed, and he never seemed stressed. He still ate normally, defecated normally, never minded being picked up, or handled, or anything. I guess I don't really know if it was stressful for him or not though, since its hard to tell. Hopefully the timer fixed that problem though (if there even was one).
Maybe if you are concerned you could just shut his light off at a certain time, and then use a smaller desk lamp type deal for around the room at night. This is what I did with my turtles while I was in my dorm room at college. After their light went out I would switch to my desk lamp, and they would just totally ignore it and go to sleep. Maybe the same will work for your snake?
Edit: just realized I'm assuming you use over head lighting on him...if not maybe just dim the lights when you feel it should be "dark" for him?