Maybe a Wisconsin winter is not survivable without a pre-prepared stash and / or a lot of luck, so let's move the theoretical discussion to - Northern California.

The Sierra Nevada mountains get plenty of snow and single digit temperatures, but the foothills are slightly more welcoming and the valleys better yet. There are also coast and interior mountain ranges that are several thousand feet high. Rain, fog, and night temperatures in the 30's and 40's are common. Mixed hardwood and pine forest with extensive scrub and brush are typical. Seasonal creeks will probably be flowing into permanent creeks and rivers, with riparian oaks, willows, poplars, etc.

So, what survival strategies for food foraging come to mind?