Based on my own experience, I have a very hard time believing 60% in 6 months, for either down or synthetic. These days I use only sythetic bags. I have several that have been stored for years, in stuff bags, and they still perform adequately. I have a several year old winter weight synthetic bag, which has been stored stuffed. I still use it for snow camping, and it still seems to work well enough. I'm not saying they don't loose any loft from compression, but my in my experience the loss is nowhere close to 60%, and takes way longer than 6 months.

Also, there is a wide variety of synthetic insulation, and one would suspect that some of the newer materials would handle compression better than some of the earlier versions.


Yes, it is very unlikely to be the difference between life and death. In most conditions, assuming you have reasonably adequate clothing, you should be able to survive a night inside a car (dry and protected from the wind) even without a sleeping bag. I'm not saying you will be comfortable or happy, or sleep much, but you will survive the night.