With a combined weight of 2.6 pounds, I have used this combination of pack, shelter and sleeping bag in temperatures ranging from 20 - 100+ degrees Fahrenheit.
Pack: Gossamer Gear Kumo
With the 7-8 lb. base pack weight I use for my thru-hikes, this is my perfect pack. The Kumo is made of extremely durable Dyneema that has withstood a lot of off-trail use in alpine and desert ecosystems. The back mesh pocket is the only part of this pack that has really shown any signs of wear. However, repairs on the mesh are quite easy and any hole that forms doesn't tend to expand.
With a total volume of 36L , 28L in the main pack body, the Kumo was the perfect size for my Continental Divide thru-hike this past summer. My longest food carry was 165 miles (5.5 days) and with the addition of the optional hip belt, this pack handled the load with grace. Pretty impressive for a 13 oz. frame-less rucksack. I've used this pack for over 4,000 miles now and plan to use it for pretty much every trip that I do.
Disclosure: I am a Gossamer Gear Trail Ambassador. However, I only accept sponsorships from companies that make products that I believe in. Gossamer Gear did not ask or require me to write this review as a part of my sponsorship agreement.
Shelter: Mountain Laurel Designs Cuben Solomid
My MLD Cuben Solomid has over 6,000 miles on it and hasn't gotten a single hole. This is the first cuben shelter that I've used extensively and I was reticent about the durability but I've been very impressed. The pyramid shape of this shelter is very easy to set up and it sheds wind very effectively. Without any broad sides, there isn't the surface area to turn the tarp into a sail.
Sleeping Bag: Zpacks 30 Degree Bag
I switched to this bag, from a warmer one, during the course of the southbound Pacific Crest Trail thru-hike. I also used this bag for the entirety of my Continental Divide Trail thru-hike. With all of my clothes on, I was able to to use this bag inside my shelter down to 20 degrees F.
When I hiked the Appalachian Trail, I used a full quilt style bag but being a side sleeper and one that rolls side to side quite a bit throughout the night, I switched to a hood-less bag. This bag is the perfect hybrid for me. My long model is only 17 oz and I would recommend going with a longer than normal model since the bags tend run a little short. I have over 4,000 miles on this bag and it is my go-to for most three season hikes.
I pair this bag with a Zpacks down balaclava and a Gossamer Gear beanie.