The last few years of experimentation have taught me a few things...
1. You do not have enough seeds. You do not have enough variety of seeds. If you bought a "seed bank", it's probably mush by now.
If you are feeding a family, especially one with growing children, you are going to need lots of food. If you have growing seasons, any food that you want to eat out of season, you have to grow in-season - and then preserve. Additionally, seeds have a life span - after two or three years, you might have very few left that are viable. I bought some tomato seeds early in the season that were fairly fresh - and have had nothing from them; some that were two years past their best-before date started growing, four plants that are not going to produce anything this year, but will next.
You have to be careful, too, on where you get your seeds from; a commercial variety might be a hybrid, their seeds infertile. So much for having a couple of packets stored away to feed you and yours for years to come.
Never underestimate the usefulness of herbs - generally easy to grow. Never underestimate the usefulness of edible "weed" species. Something that propagates easily, has some nutritional value, and tastes bland is far better than something that has to be looked after very carefully to produce a "miracle" food.
2. Also consider trees.
Food trees can be a lot easier to look after than vegetable patches - but need a lot more room. Nuts store fairly well, although you may have to be careful of rats. Fruits are useful and tasty. I have ordered myself several more trees, I am determined to get cinnamon to grow, cloves too when they become available. My coffee trees are going well, I will have to plant them out. I have ordered myself another carob tree, the one that I have is growing, albeit slowly, I want to have one in a pot, see if I can get it big quicker. I've been reading up on the nutritional value, seems good, plus the seeds apparently have a usable gum.
There's also the consideration of soil health - trees are important for ground water cycles, for retaining top soil, and if you choose correctly can help with soil nitrogen levels. Nitrogen in the soil is important - and a number of plants are able to extract it from the air. Or, more specifically, host the bacteria that can extract it from the air, and put it into the soil. Which leads to...
3. You don't know enough about chemistry, agronomy, forestry, and geology.
If you have to think in the long term, you need to know what to know. You need to know what local resources are available for use, how to make good long term use of what there is. Plus, if you don't know why having Nitrogen in the soil is important, you'd better learn; if you don't want to learn, give up now. Castor seeds have an incredibly powerful poison in them, but the oil is very useful, especially if you have engines that you can run. And speaking of growing things...
4. You aren't going to be able to hunt game. You need to start breeding and feeding your own animals.
Well, if you live near a major game migration path, you might. For starters, think about what game is close - and what you could capture on a day's outing when you can only walk to and from the game. Unless you and your family go strictly nomadic, you aren't going to be able to catch much. And multiply yourself by dozens, even hundreds, of others who think that they can...
5. Your bug-out location is probably someone else's backyard.
And they might not be happy that you are picking through their property.
6. You can't do enough by yourself, or just you and your immediate family.
Friends will be the key to survival long-term. More people to spread the needed tasks, more people to protect you...
That's what I wanted to say at the moment.