Some interesting ideas here. I think this is why they started adding lot challenges to the game, it allows each player to make the game as difficult as they'd like.
In fact, it you own Cottage Living the Simple Living lot challenge will make it necessary for your Sims to have the ingredients in their inventory before they can cook recipes. They can either grow them themselves or order them on a computer or phone and they'll be delivered.
I've been playing a survival challenge with all of the lot challenges activated and it does indeed make the game a lot harder. The most deadly challenge is the Creepy Crawlies one from Jungle Adventure. Your sim has a small chance of being poisoned if they're bitten, and if you don't give them the antidote there's a chance they'll die. Lost one sim to that one already since they're not allowed to leave their island to find the antidote in Selvadorado.
So maybe add any challenges you have to increase the difficulty. Off the Grid was added to base game, and at the very least it will make your food spoil faster and limit your plumbing options.
