Reddit mentions of Old Wisconsin Premium Summer Sausage, 100% Natural Meat, Charcuterie, Ready to Eat, High Protein, Low Carb, Keto, Gluten Free, Beef Flavor, 16 Ounce

The 100% best solution is to have a propane burner along with a High Pressure Hose so that you can use normal propane tanks that you'd get for your grill. Then keep maybe 3 of those full and ready to go and that will maintain your ability to use your stocks for a good while. (Note: I didn't dig too deep into direct compatibility of those two items. I just listed them as an example so you could see what I was talking about.)

Barring that... it's a question of shelf life vs cost. Obviously MRE's would be one of the better options, but they're pricey and it's best to store them in cool environments which may not be doable for everyone. Mainstay 2400 Bars are available at Walmart for $5 apiece and are fantastic for BOB's due to their hardiness, but surviving on those for any length of time would probably be miserable.

Dropping into normal foods... yeah, a well stocked and rotated pantry is the way to go.

• Peanut Butter is high calorie, flavorful, and a thing most people can use regularly anyway. If you have forewarning you can try to snag extra bread from the grocery store. Barring that, YouTube how to make bread and get busy in the days leading out to the outage. I think whole wheats tend to last a bit longer, and I think things like wrapping the loaf in cling wrap then sealing it in Tupperware can help, but I'm not a baker so I can't say for sure.
  
  
• Canned meats are a good call as the next in lineup. Tuna is obvious, but you can get canned chicken as well. Add some crackers into the mix and whatever seasoning you like (I'm a fiend for Lemon Pepper ) and those are meals on their own, though a bit pricey. Spam and tinned ham, while less pleasant uncooked, are also edible.
  
  
• The good canned soups are fine right out of the can. Obviously they're less pleasant not being warmed, but that's actually something you can probably remedy to a degree just by having tea candles under them. There are also several camping stoves that do not require propane, and you can of course just have some sterno on hand too.
  
  
• After that... well almost anything canned can work. Refried beans or Baked Beans cold out of the can are edible if not the most pleasant way to eat them. Good return on calories for those, and if you have a large family they are available in #10 Cans which will save you a lot on cost. Canned Veggies can be added in to other meals without heating, though the calorie returns on them make them inefficient. Canned/Jarred Fruit on the other hand can be a delicious morale lifter.
  
  
• Bars of Velveeta keep for a surprising amount of time in the pantry, and there are about 2240 calories per full bar of them. That's another great option for throwing on crackers. Crack open a jar of salsa and add a bit to each cracker and that's tasty eating.
  
  
• While it's not my favorite thing ever, Summer Sausage is around 1600 calories for a pounds of it and is shelf stable for a while when unopened I believe, though check the packaging to be safe. I believe Hickory Farms Cheese/Sausage lasts for months, though if you're not eating it regularly I don't know how feasible it is to have on hand consistently or in time for a disaster like this.
  
  
• While the ideas could probably keep going, I'll end with trail mix. It's easily obtainable at a lot of locations, includes nuts, candy, and fruit so it's palatable, and tends to have a fairly high caloric return. Add in other snack foods like beef jerky, chips, and candy/energy/protein bars (also available at a lot of locations) and it should be fairly easy to find enough ways to get your daily calories in in the short term without needing to heat things up.

We could use food, such as this Add-On sausage. The almonds on my Add-Ons wishlist are even cheaper. (There are also cheaper and higher priority items on my Prime Pantry wishlist, if you have free shipping credits).