You live in the west. You are spoiled and pampered. Trust me. Central heating, hot water, a hospital you can go to if you catch pneumonia. We’re so used to the concept of being able to flip a switch and make heat that when the cost of it goes up we bitch.
It’s not going to exist post apocalypse. At all. Ever.
Imagine it, mid winter. It’s snowing and you’re out doing necessary chores. It’s so bitterly cold you want to cry, but you don’t because the tears will freeze on your face and make it worse.
But instead of a warm house and hot chocolate to come home to, you have a drafty, echoey ruin, your only heat from a bonfire that chokes as much as it warms you.
It’s going to be unpleasant.
How to cope? Well, remember that across most of the world, it’t temporary. That;s the main thing. Spring and summer will come and with them will come sun and warmth and growing things.
But people die from cold, so how can you make sure you survive till next spring?
Clothes:
Think ahead. Make sure you have lots of easily packed warm clothes in your go bag, plus the materials to make more. We’re talking those ugly thermal undies, socks, scarves, gloves, hats. Have plenty. When it’s time, layer them. Top them all with waterproof coats and boots so the damp doesn’t get in and kill you.
Fashion is less important than staying alive. I’ve already covered learning to knit (I made a scarf) and weave so you can make more clothes when yours start wearing out.
People:
Have people around you. Sure, you’ll be competing for resources, but human beings pump out roughly 1 kilowatt of heat each. That first winter, everyone except who’s watch it is should sleep in one pile together. It worked for our neolithic ancestors: It can work for you.
Food:
Eat lots of carb and fat heavy food. As much as you can. With more energy to spare your body can keep you warmer.
Fire: Learn how to make fire. Now. I mean really, now. Also learn how to make charcoal ovens, so you have long-burning fuel.
Also, charcoal ovens stay warm with little smoke for a long time.
Hopefully you’ll survive the winter without too many bits dropping off.