I said this in another thread so just copying and pasting it here for your benefit, was in relation to feeding but same goes for activity levels.
They won't feed during winter, some occasional piggy ones will, but majority won't. IF there is a UNUSUALLY warm day or two, you can offer food and they might take it, but not likely especially how cold this winter is. Snakes brumate a state or condition of sluggishness, inactivity, or torpor exhibited by reptiles (such as snakes or lizards) during winter or extended periods of low temperature This subterranean torpor is not a true hibernation … but a cold-blooded version of slowing down called brumation. Thus you don't see snakes out and about in winter unless on those rare few warm days they're suddenly out and about as they're opportunistic hunters and take advantage of that to warm up and hunt, but they don't need to.
Yes in captivity we keep them warm and give them a good environment, but they're hard wired to the seasons, you'd have to have a completely sealed house with no airflow and perfect climate control through the whole thing to convince a snake that it's got the season wrong. Regardless it's good for them and natural to go through the seasonal cycles.
They won't lose enough condition for it to be a concern and in August/September they'll start munching away. It's hard to not worry about them, I get it, but you have to re-evaluate your ideas of how animals function when it comes to reptiles, they're efficient little machines and know how what they need.
