Not sure why you booked the ticket (to Changsha in Jan 2024), before researching on where to go. Assuming you cannot reschedule you flight, here are my comments:
Cold Weather
Depending on your tolerance for cold weather, besides wearing the appropriate winter clothing, please pay attention to protecting your
feet (wear thick socks, wear shoes/ boots with anti-slippery grips), your
hands (gloves), your
neck (add scarf if your jacket does not offer enough protection), your
face (mask would be useful), your
ears (most winter jackets should have a head cover).
张家界旅游乱象
I went there in summer 2017. I joined a local tour group (via wechat), & had a bad experience. I just googled
张家界旅游乱象 & I think this article (dated 2020) summarized quite well:
真实遭遇!张家界旅游的连环骗局 - 知乎 (zhihu.com)
I suggest you do your research & plan your own detailed itineraries instead of joining local tour groups.
My personal view is: the must-go attractions are 张家界国家森林公园景区 (need at least 2 days, I recall can re-enter with same ticket) & 天门山景区. As for the man-made 玻璃桥 - can go if you have not experienced something similar before. I watched an open-air night-show, but can’t recall which one, & also not sure if it’s available during winter.
Last but not least, I still think winter is a bad time to visit
张家界, esp. If you do not have experience with handling winter seasons.