One's neighbors are going to be a serious issue. There are some folks that choose to live in the sticks because they are hiding from the law. and folks that will steal you home from under you, and post SHTF who is to prove whose land is whose, especially some one new?
TNT and electricity are the only ways to fish, especially when you have a lot of mouths to feed. Since there are better uses for TNT, I would go with electricity...a small gas generator or a military surplus hand crank generator.
Hey I bet there are a few of us on here that could give some first hand advice on how to burn poop with a bit of diesel fuel.
Surprised nobody recommended an "Incinolet". They work fairly slick, and you said you had power at the cabin. I have a couple of friends that have them in a garage and outbuildings, and a relative who had one at a cabin that sat next to Lake Superior on a granite shelf. Just looked it up, and the website pretty much describes it: Official Home of the Electric Incinerating Toilet