Successful winter backpacking for me is dependent on 2 main factors:
It can be challenging to stay both warm and dry because you’re exerting yourself while also being surrounded by wet snow and sometimes rain. So you’re getting wet from your sweat and from the elements. In summer camping, if you’re sweating while you hike, you can usually just live with it and your clothes will dry off when you stop hiking. In winter camping, if you stop hiking while you’re wet, you will freeze.
So, how do you stay warm and dry?
Let’s borrow some content from the internet.
The following is borrowed from SectionHiker
Many winter hikers use a four layer clothing system:
During the day when you are active, you’ll most likely be wearing layers 1-3, in addition to gloves and one or more hats, although during periods of high exertion you may take off layers 3 and 2 to vent as much extra heat as possible in order to avoid sweating. If you do sweat, the function of your base layer is to move the sweat away from your skin and into layers 2 and 3 where eventually evaporate without chilling you, because it’s in a higher layer.
Generally, you really only need the 4th insulation layer when you stop for a break, for hanging around camp, or for very cold summit conditions and high windchill.
When you go to buy winter hiking layers, it’s tempting to buy a jacket that combines layers 2 and 3, the insulating layer with a wind proof shell in order to save money. There are also many coats available that are waterproof hard shells with a built-in fleece liner, snowsport jackets that have added down or synthetic insulation in them, or so-called 3-in-1 component jackets which only contain 2 components, an exterior waterproof/breathable shell and inner fleece/insulated jacket that can be zipped out. While these might be suitable for downhill skiing or riding the school bus, I wouldn’t recommend them for winter hiking, backpacking or mountaineering.
Instead, my advice is to implement each of your layers using a different best of breed garment. This gives you the most flexibility and let’s you select garments that are optimal for a specific function. It’s also far easier to control your heat level with individual garments versus garments that combine two layers into one, and the failure of a single piece of clothing (broken zipper, for instance) will only compromise one of your layers and not potentially two.
Keep it simple: a separate garment for each layer.
The Scouts used this information for our trip on Snow Creek Trail.