Cold isn't an issue after a trip to the mountains. 30 minutes is good but the resting time is actually a good time to get up and move around. Your Viking may be dead and needs no sleep but humans need to move around on a regular basis. Swigging a beer doesn't count, nor does eating a bag of Cheetos.
If you have 1300 game days, it may be time to take a break if this is game breaking for you. Or mod your game, or use devcommands if you are just building, easy peazy. The rug bonus was OP and needed a nerf.

For fighting bosses that take a long time, not sure what the answer is now. IG obviously knows it's a problem but they have recently decided to put the brutal into what was certainly up to now not in any way a brutal survival game, despite their description otherwise.
The fun of EA.
Travel safe.