I was stationed in Alaska and had to sleep outside in the cold, once for a month straight. Last winter my heat consisted of just a 1500 watt heater pointed on my face and a electric blanket, with foil reflectors (bubble wrap foil meant for HVAC) around a Walmart leather couch. It kept me warm during a covid infection in December.
I strongly recommend people invest in electric blankets, if I had to go elsewhere in the house I'd have to unplug and plug in elsewhere when working.
My long term goal is to get a van and live in it. Winter months will be my sleeping bag on about 3-4 packing/moving blankets and a thermal blanket to keep the heat from getting sucked out beneath, with a buddy heater and propane tank for emergency backup. I'm not all that interested in living in a house anymore. Big waste of money.
I did just waste $200 on a jacket today. It fits under my rain jacket. I'm hoping it fits inside my rucksack in my sleeping bag, I haven't tested it out yet, about to. I'm hoping I can make everything work until spring and get a van, but if not I should survive anyway.