I agree with Rosequartz, food left out to cool and refrigerated should be OK, especially if you reheat it thoroughly before eating it. Most food if thoroughly reheated to boiling point should be safe to eat.
I do not worry about having to buy larger packets of food because I portion it out and freeze it. I just get one slice rf one small portion out of the freezer as I need it. This applies to sliced bread, all cheeses, soft and hard, vegetables and meat. We eat a lot of casseroles and stews. I will make casseroles using a pound of meat and then use a third of it for a meal for DH and I and spoon the rest into two plastic containers, which I label and freeze.
At any time I will have 10 or 15 home made ready meals waiting use in the freezer. Most food will last in the freezer far longer than recommended. The recommendations are based not on safety but flavour. Personally the only food item that I have experienced a decrease in flavour quality with is bacon - it was still eatable, just not as good.
'Sell by dates' are aimed at Supermarket stock control not eatability and most 'use by dates' incorporate a wide margin of safety. And dry goods and tins have an indefinite life. Manufacturers only put 'sell by' dates on them because of the inflexibility of EC laws and, again, are based on flavour not safety.
So far, nobody has got food poisoning from food I have prepared, but I do cook food thoroughly and do not like meat to be still red or even pink before I eat it. As I said we eat a lot of casseroles and stews bcause they need hours of long slow cooking.