I have been on some variant of a keto diet off and on for ages - the last 5+ years nonstop - and perhaps half of my calories on any given day come from either butter or coconut/MCT oil, dropped into my morning coffee.
Our plan last year was to bring coconut oil as a fat source when we camped. Due to weather, we ended up in a cabin, which was nice, but I still had coffee with coconut oil and butter every morning.
I don't say this trying to be that annoying 'keto evangelist' but once your body gets used to straight fat for morning fuel, you can go all day with steady energy - I rarely even think about eating lunch on a normal day, even if I'm outside. Carbs may be better for intense short bursts of energy, but for 'go all day' sustained energy, fat is where it's at.
Fat is incredibly calorie-dense. Coconut oil is great. Oily peanut butter is great. Butter is great. But, yeah, eating straight fats takes some getting used to.
Also - look at prepackaged biltong. Yes, the stuff Cliff Gray advertises. Yes, it's expensive, but it's darned near the perfect backcountry food source, with a great mix of protein and fat and a bit of salt for electrolytes. I think I could eat it for an entire trip and not get tired of it, either.