And the keyword you neglected is

they

A community of like minded people, with sufficient supplies to make it through The First Winter, is potentially going to survive. A lone individual who figures "My dad survived out here in the 50s with just cardboard boxes for shoes when he was walking uphill, both ways, in the snow. The fuck you talking about 'climate change'?" is not.

All of which gets back to the idea that a gun is going to help at all in those scenarios which, once again, gets back to how easy it is to actually sneak up on people (within 200 meters is an easy shot with a rifle. especially if someone has an optic) or the simple logistics of keeping watch while doing all of this Survival.