There are outfits online where you can order whole menus of dried canned goods. You can get weeks, months, or years worth of assorted items to make a well balanced diet. If you have that, and can supplement with garden grown veggies and some meat, you could make it for quite a while.

That's one thing I haven't heard anyone mention. If you're planning on growing some of your food in a garden, you might want to stock up on seeds. You can vacuum seal them and put them in the freezer to extend their usefulness. If you have a certain variety of stuff you like, you could just exchange them each spring when you went to do your planting.