It is quite easy to stock up on food for one month (in fact, the experience of the covid-19 pandemic showed back in 2020 that every home should have some food supply for at least three weeks in case of possible isolation) and your plan is also quite suitable for this. It is more difficult to foresee the option if you have to do without going to the grocery store for say a year or two, for example, in the event that the entire civilian infrastructure is destroyed by a nuclear strike. A few years ago, I experimented with making universal dry food for people and created my own recipe for granola - baked oatmeal in honey with the addition of nuts and dried fruits. When vacuumized, granola retains its taste and nutritional properties without noticeable degradation for at least six months (this is from what I personally checked, I think that it is possible with some stretch to extrapolate the result obtained for 25 years, because there is nothing special to spoil there). After creating such a stock of dry food with a long shelf life, you only need to take care of a water disinfection device and iodine tablets in order to have a chance to survive the apocalypse of any complexity. Hopefully I won't need this skill, but I'm glad I have it.