FWIW, here’s what I typically carry hiking solo on a cold, mid-winter day-hike of any substantial distance or elevation. It seems like a lot when listed but, like others have said, I like to carry what I need to spend the night wherever I might be. With groups, I carry mostly the same stuff.
Fleece Hat (sometimes w thin liner hat)
Gloves (waterproof, well-insulated fatties)
Long sleeve wicking tee
Mid weight Bergelene tights
Summer rain pants
Waterproof, insulated boots
Extras clothes I carry:
Extra long-sleeve wicking shirt
Heavy fleece pants
Extra gloves (mid weight fleece)
Extra pair warm socks
Down puffy Jacket
Winter bivy sack
Rain cover for pack
2 Water bottles in socks or insulated sleeves
Extra batteries (1-2 sets)
First Aid Kit
Optional things that depend on hike:
20 degree sleeping bag
1-liter vacuum flask of hot tea
I'm sure it's not 100%, but I think it's close.
For overnights, add stove, fuel, sleeping bag (-40), full length thermarest, possibly tent, utensils.