Hmm,

Actually heading for the hills, as you describe, would require a fundamental lifestyle change for nearly anyone. It would be tough goings, especially in the winter months. Assuming you don't have access to a pre-built fortification (like the cabins I would seek out), you are stuck with temporary accomodations and no sure source of food or water. While that is fun for a weekend and a nice challenge for a week or two, it is grueling for extended periods. Oft times it will require frequent relocation, and everybody's supplies run out eventually.

Things have to get pretty bad down in the valley before the prospect of hitting the trail sounds like a suitable alternative. Take the examples I cited earlier (pandemic, civil unrest, invasion) that would make me flee my home in the first place, and then multiply them so that any civilized location would pose significant risk(global pandemic, world collapse, world war, apocolypse), and that is about what it takes to make heading for the hills a truly viable choice.

Heading for the hills should mean leaving all civilized comfort and convenience behind, with only the stuff you can pack with you to live off of. I believe that was the original intent. It doesn't include heading for the vacation house or that convenient bed and breakfast chalet off the beaten path, it means roughing it, or it should in this context anyways.