Survival situation, you can easily get away with 1800 kcal/day. 4 people, 3 days = 21600 kcal.

Rice, mostly starch, around 3600 kcal / kg. So 6 kg for three days. That's 12 western or 0.6 Asian packs. Its like half a cement bag in volume.

Or you can get bulk ramen. A box of ramen has around the same size as that rice above, its 30x360 = 10800 kcal. So needs a bit more space but you can eat it raw!

Most bang for the weight/volume is fat though! Fat stores 7 kcal/g, protein and carbs just 4. And the tastiest way is nuts! So peanut butter for example. Or Snickers. You can also put peanut butter on raw ramen. Get a bag of chips too, you can use them as fire starters!

Don't forget other stuff though:

• Crank operated radio
• Combat first aid kit, ideally with Israeli bandages and a tourniquet
• Power bank with foldable solar panel (+ all the cables you need)
• Water filter
• Magnesia fire starter
• Lighters (plural!)
• Multitool
• Compass
• Cash
• Paper map of the surroundings
• Head lamp
• Bunch of paracord
• Couple needles