Go with the Stone Glacier Avail or get the X Curve frame and a smaller pack that fits your needs currently. If, when, your needs increase sell that bag and trade up. Lightweight, durable, made in the USA. Can’t go wrong with these guys.
Basically doing what you described from TN to WY to BC with these.
https://shop.gohunt.com/collections/kenetrek/products/kenetrek-mountain-guide-400-medium