I don't think it's as simple as you say under those conditions but the option is there, I doubt they haven't discussed it
Discussion
cannibalism is always wrong. period. feed the ones that fall to the dog, if it still is alive, but fuck that.
unless you are at sea and can't craft a way to catch fish, then maybe, maybe, you can eat the person who died of natural causes
in every other situation there is always a place to go, and things to eat in that place, eventually somewhere