Another thing that can really help with this is a hot water bottle. You can put it on your lap, or under your feet and it really helps you keep warm if you are sitting for long periods of time. Helps if you put a small blanket over your lap as well. Usually lasts for a couple of hours before you need to refresh the water in the bottle.
I was playing cyberpunk this winter with a 4090 at 4k RT on and all settings maxed. My desktop took the living room from around 50F to over 72F. My A/C turned on! It was genuinely insane
That rig probably can generate around 1kW of heat, just like average space heater.
You have a very small living room if that alone can heat it up from 50F to 72F.
