I've been looking into Next Mile Meals too but haven't bought any yet.
I only do day trips here in the East, but I normally pack macadamia nuts, pecans, walnuts, cacao butter and maybe some jerky. Macadamias are my favorite. Almost perfect keto macros and calorie dense little suckers.
Those packets of nut butters are ok if you can find one not loaded with sugar. I'll probably just make my own this year in a little zip lock bag and use some allulose if I want it sweeter. Coconut butter is another favorite of mine. Eat straight, mix in cacao powder, nut butter, berries, crystallized lime powder...whatever you fancy.
I also take some sea salt to put in my water. I see no reason for carbs in the woods if you're on a ketogenic diet.