I'm up to day 4. When you crossed the river, what was going on with your feet? I assume your feet got wet, and you dried them out? I've never done anything like what you did, just based on your first four days, but I'm working on the Adirondack High Peaks. Mostly day hikes, but I have some overnights planned this fall. Depending on what kind of suggestions you want, I'm happy to describe my hikes. The High Peaks are 4000-5000' from trailheads around 1200-1800'.
I think just lack of circulation. I had frozen/numb feet for a few parts of the trip (especially as we hiked off glacier in the 3rd-ish week) from standing in icy water, and ended up with a tiny yet convenient bit of nerve damage from it. Mostly loss of pain sensation - which is nice while my fiance and I take dance lessons! Haha. And ooo those sound like fun! Are they fairly close together to do a loop? I don't live near there, but it would be fun to make a trip out of them. They look beautiful! Especially in the fall (or at least from what I can see on google images ha).