John the Baptist lived in the wild, wore a camel hair coat, ate locusts and wild honey.
He is a pattern and example of what I am talking about - being able to survive off the grid.
By the way, locusts are clean animals in Mosaic law.
Suppose one does not have a pot for boiling water to sterilise the water.
But suppose one does have a hollow in the rock, or bowl which will hold water.
Then one can fill that bowl with unpurified water, make a fire, heat rocks in the fire, then drop the heated rocks into the bowl of water, and enough hot rocks will get the water to boil for a few minutes, making it safe. The water can be filtered through a shirt first to remove larger dirt.
What does one do for food?
John ate locusts and wild honey. Eat these if you can find them. Fishing is good. So is using snares with a noose to catch animals, if one has wire, or perhaps using the rope we made earlier.
Watch Bear Grylls and you will see he eats anything. And he is a terrible cook. For him it is about forcing each disgusting morsel down as quickly as possible, followed by a grimace and a comment about how every morsel has calories. He is able to switch his brain off to the disgusting nature of the maggots or whatever he has just eaten.
I personally do not eat anything unclean, as defined by Leviticus 11 and Deut 14. But if Mr.666 was hunting me on the mountains, I would be lifting every rock to see If I could find termites, scorpions or snakes. Yes, I would cook and eat Satan's buddies, snakes and scorpions. These are the easiest to catch. It's a "fear factor" mental issue one has to overcome to bring oneself to eat disgusting foods. And snakes apparently are quite good eating.
I would make sure that everything is well cooked, to kill all parasites. Bear just eats earthworms, and maggots and termites after giving them a rub on his pants to remove the sand. I would want them a little better sterilised and better cleaned.
One may ask, if eating unclean foods is against your religion, why are you prepared to do that, and will it not make God mad at you for compromising your beliefs? I know that taking Mr.666's mark will make God mad at me - that is why I am hiding in a cave after all. If I go ahead and eat an unclean animal, the worst it made one is "unclean" until sunset, when the clock reset, and one became clean again, especially if one had a wash.
OT "uncleanness" is about being ritually impure and unable to go into the temple in Jerusalem in this impure state. But I don't want to go into the temple in Jerusalem, especially as Mr. 666 will have made it his own, and will be worshipped there. So by being "unclean" from eating a snake, it will just disqualify me from doing something I didn't want to do in the first place. I would be more worried about getting parasites.
Obviously Bear Grylls takes antibiotics and deworming medicine off camera - which we will have limited access to in the end time. And if one does not eat, one will not last a thousand two hundred and threescore days (Rev 12:6).