Hi Piper - I'm a noob on this board, but I found this thread and wanted to share my perspective with you. I've hiked ketogenic for the past two seasons - gearing up for my 3rd now. I have found hugely positive results from keeping my carbs under about 100g/day while hiking all day long.
I rely on lots of coconut oil and butterfat (both in powdered form), make a home-made trail mix (which according to a fitday analysis is practically a superfood in and of itself), and paleo- (or at least primal-) FBC meals, home-made, of course. I've forgone the pemmican as superfluous and boring.
I've hiked and been active all my life, yet still found myself in my late 30's, out of shape and obese. Despite that, I would still charge thru the Cascade and Olympic Mtns like nobody's business, tearing myself up the whole way. It would take a week to recover from a weekend hike, we won't talk about longer hikes. Going UL didn't help much.
Going keto did. We'll skip over what led me to go keto to begin with, but it left me feeling so strong and vital, I couldn't wait to hit the trails. I found being VLC provided me limitless energy and increased strength, no cramps and spasms at the end of the day, huge mileage every day (I now do 2o miles min/day, vs 15 miles max/day), and a happy mood the whole time. I can carry twice the amount of food in the same bear canister, making for much longer solo trips.
For going keto, every personal measure of hiking fulfillment has gone up. Of course, it takes a bit of prep - my transition lasts about 6 weeks, and it's not fun, to be honest. I am thinking that next winter, perhaps, I won't indulge in holiday carb-binging... see where that leaves me going into training season.
Anyway, that's my n=1. I'll never hike loaded down by carby food again. Awesome thread!