Before modern times, back in the dark ages, back when I was growing up on the farm, the chickens pretty much took care of themselves. Chickens raised with a flock that forages can feed themselves if they have enough room and the ground is accessable. If the ground is covered with snow or is frozen then they need supplemental food. If they have been brooder raised and are used to somebody providing all their food, then they don't know how to forage. Our chickens were not brooder raised. The broodies took care of that. I grew up in an area that usually did not stay below zero Fahrenheit for long and the ground did not usually stay frozen all that long in a stretch. Most snows melted off after two or three days. Different areas would have different conditions so they would have to handle the situation differently.
We fed hay to the cattle outside on the ground. The chickens could forage through the leavings for some grain, but mostly they just foraged. If it was pretty rough out, such as the ground frozen or covered with snow, maybe a strong blowing snow-storm that lasted a day or two (I don't want to say blizzard because I respect what others go through in a real blizzard) we would feed them some shelled corn to get them by. If the pond was frozen over, we would break the ice so the horses, cows, and chickens could drink.
We did not go to the bait shop and buy them crickets. We did not knit them little mufflers and wrap them up at night. We did not provide any supplemental heat. We gave them a dry, well-ventilated, draft-free place to sleep at night, helped them when times were rough, and let them be chickens.
With most people on this forum, chickens are pets. The chickens do not know how to take care of themselves. I'm not criticizing anybody for how they keep their chickens. I don't keep my chickens the same way my parents kept theirs. But you asked how it was.