50 liters is huge. I'd think in terms of smaller rather than bigger. I'd suggest working with what you have now, and when you figure out how to get to where you don't need 50 liters, consider something smaller. This week, I figured out how to load a 33 liter pack for a 3 season trip of the same type. Not that I'm making it or anything. But I'll give a tip for figuring it out. If you can make it for 4 days, a year is just 90 4 day trips. You should be able to resupply in most places every 4 days.

Check out the American Discovery Trail which passes through your area. I'd skip the parts that are too hard.