Freezing cold will inhibit function of your fuel, or outright damage your water filter, and any devices with batteries, so it's important to wear these in a pocket during the day, and keep them in your sleeping bag at night.
This is my packing list as an example.
In regards to the next 3 items, the following link recommends wool felt over fleece. I include fleece because I've used it and it works well for me.
I am not a fan of synthetics because they get stinky. They are overly hyped / marketed because they produce the most profit as they are super cheap to manufacture. While I recommend wool for winter, based on this research, and some bamboo socks I love, I highly recommend bamboo for summer activities,
I have some Ex-Officio underwear that is somewhat magical in its ability to not stink. I don't know how they do it. However, it doesn't feel as comfortable as cotton. I have some wool underwear that compares with cotton, but it isn't comfortable in a different way: it doesn't have a good pouch for the man parts like Ex-Officio underwear. The ideal would be bamboo underwear with Ex-Officio fabric stitching.
Watch out for viscose rayon passing off for bamboo fabric.
Part of your clothing system is a sleeping bag.
You should match a sleeping pad to your sleeping bag: see the section in the shelter article.
Some people don't prefer hydrophobic down coatings. Others do, especially if a new feature can be marketed to promote additional sales. I might assume that hydrophobic down does not largely affect breathability? Considering that Aegismax rates their treated down as 700 fill power, and untreated as 800 fill power, I believe the following statements on Reddit:
With treated (down), I noticed that it has a significant “clumping” effect as well as a slight weight … untreated just lofts up more easily and this goes a lot further in a project, and so you’ll need more treated to achieve the same level of loft.
So consider your climate and length of trip. AT? Sure, go treated. You’ll presumably have less time to let things air out and Appalachia is a very muggy/rainy place. I made TQ’s for my buddies who are starting this month and we settled on treated. … If you are doing long weekends, shorter-long hikes, live in an arid climate, I’d say untreated all the way. Laser_Dogg
I have two G1 bags that I bought for my family. I’ve used one of the myself for a couple of times. I washed one of them with Nikwax down proof, and it lofts up better than the unwashed one. SmalandOutdoor
The reason you would use a 35F bag for a 45F temperature, is that sleeping bag ratings are usually false, and you have to add 10 degrees to know what you actually need. Excluding Aegismax which Reddit has said to be very honest in its temperature ratings. However, to fully know your bag, you have to test it yourself at different temperatures. Also make note of the humidity level.
You can make due with a less warm sleeping bag, by wearing your clothes to sleep. A base layer is better preferred by the community over a sleeping bag liner.
They make some sleeping bags that you can wear walking around, but they fit loosely and it would be hard to do much in them besides sit in place.
I'm not a fan of quilts. The bottom of the sleeping bag does compress under you, but it also wraps around you rather than the sleeping pad, and the immediate places around the contact points are not compressed.
When selecting any down product, keep in mind that it may be worth it to have baffles instead of sewn-through stitching:
I have nothing to do with Aegismax. It just happens that they are the only down sleeping bags I ever bought, and I'm happy with them. I'm not rich ok?