"Premade emergency food supplies are an option"- They certainly are an option, though the nutrition is generally pretty poor, as is the cost per calorie, as is the quality and taste of the food. They seem to be marketed to people who are looking for an easy way to check off a fear from their list. While I understand the market, I would estimate a trip to a bulk food supplier or other discount retail store that sells in bulk might address those concerns even if products are not all labeled specifically for emergencies.
In estimating the optimal food storage, I'd suggest also considering:
Psychological advantages of being overstocked- if you have three month's worth of food on hand, you're going to feel better if there's a storm that closes down roads and stores for 4 days than if you just have a week's worth. Even worrying about running out of food takes a toll even if it never happens. This suggests greater storage.
Cost advantages of bulk buying, especially for foods you already eat- I eat a lot of nuts. Just buying a big 10 lb bag of macadamias gives me 33,000 calories, 2 weeks worth of food. They last a year so I always keep 3 or 4 in rotation, with a subscription option that delivers another ever 3 months. Between that, other nuts, some bulk grains, a few pounds of dried fruit, pasta, canned peanut butter, canned tomatoes, tinned fish and some tubs of whey protein, I probably have 3 or 4 months of food just in my apartment cabinets without any specific intention of preparing for a disaster. It'd rapidly get a bit redundant by itself, but whatever, it'd be nutritionally complete enough to survive with foods I enjoy. Everyone's diet will vary, but I'd suggest contemplating bulk buying as a means of frugality and time-savings would offer the collateral benefits of emergency preparedness. This suggests greater storage.
Fat tail risk- For what kind of an event are you planning for and what's the associated duration of disruption and the likelihood it occurs? Inclement weather, an earthquake, a nuke, a siege, prolonged breakdown in basic services and massive unrest? More serious events merit greater storage, but are also far less probable. Additionally, consider the opportunity cost both within preparation for the event and generally. Preparing for more serious events may warrant greater marginal benefits by first making investments in other equipment or infrastructure before making dramatic investments in food. And generally having, say, years worth of food stocked will carry additional opportunity costs-space, cost of storage bags/bins/shelves, time costs of managing food rotation, risk of loss due to food spoilage or insect/rodent infestation etc.
"Premade emergency food supplies are an option"- They certainly are an option, though the nutrition is generally pretty poor, as is the cost per calorie, as is the quality and taste of the food. They seem to be marketed to people who are looking for an easy way to check off a fear from their list. While I understand the market, I would estimate a trip to a bulk food supplier or other discount retail store that sells in bulk might address those concerns even if products are not all labeled specifically for emergencies.
In estimating the optimal food storage, I'd suggest also considering: