The Garmin High Sensitivity GPS tool is a potentially game changing piece of survival gear that employs a quad-helix antenna and GLONASS receiver to provide actionable GPS data even when you’re in the gnarliest locales. With its comprehensive selection of pre-loaded US topographical reference maps you’ll be able to plot an effective escape route from even the direst situations.
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!