I can’t speak to your question specifically but I will say that it seems good to have some fat on you. All the athletes I know that are very minimal body percentage tend to get more injuries from what I’ve seen. I think your body needs a certain amount to be optimal. Having little to no fat may not be good. Interested to see the answers to your question tho.
Even if there was, humans now generally have lifestyles where it wouldn’t matter (we live in heated houses, food remains accessible all the time, etc.)
Personally, I don’t weigh myself regularly but I think my weight probably does fluctuate seasonally - in winter I’m less active, not outdoors as much, garden is spent, and there are more holidays where food is a big part of the celebration. So there are many reasons someone might gain weight in winter but again it’s more related to our current lifestyles/environment than any biologically driven “need” to have extra stores. FWIW, it doesn’t appear to harm my health.
Like the other commenter mentioned there are risks when body fat is too low (can affect performance, hormone levels, and recovery from illness), but that can happen at any time of year.