Based on this crude but honest assessment of the general public's affinity for the common bicarbonate, you'd be surprised by how much survivalists are into it (#2 on the list of "things for preppers to hoard"). They must expect some pretty serious hankerings for tasty leavened baked goods, or they have extensive phobias about the funkiness of their nuke survival backup plans.
The survivalist hard-on (yep, and I'll do it again, too) for prophylactics untouched by chemical pleasure-enhancers is the result of drilling deep (told you) into the magical properties of our latex friends. According to our research, these flexible, durable, waterproof wonders will be as much of a deciding factor in your dystopian longevity as fire and can openers.
To me, the best option is to store emergency food. How much? If you have none, store enough for a few days. If you have enough for a few days, get enough for a week. How much you store depends on what time frame you think you're at risk for having to be completely independent. The early settlers of the southwest liked to store enough food for a whole year and still do to this day!