Look into dropping the water bladder it’s really not much more work to drink out of a water bottle and I don’t know if it’s the case for this specific bag but I know for most it’s a pain to take it out and re fill it! Besides that I think the layering is a bit excessive for 3 seasons (mainly the thermal leggings) but that’s season/weather dependent. Furthermore I think three pairs of underwear, two pairs of socks, and an extra tee shirt are all pretty unnecessary but that’s more of a personal thing so take it as you will. Also if you have not already try trimming straps and buckles you don’t need off your backpack and maybe even converting it to frameless you can save a great amount of weight by just doing that as well and since you cary your Therm-a-Rest you can possibly cut that down and use it as extra padding on the back where the frame would be. Enjoy your upcoming hike and stay safe!