Should be one safety razor - just the blade. Just need a steady hand...

You're budgeting for the weight of a safety razor?

Surely the hunting knife you use to kill your dinner when combined with the mirror you use for starting your forraged twig fires, that would be the ultimate solution.

...or just not shave for a few days. I guess you could do that too.

Think of the weight of all the extra hairs though.

That's a good point. Personally, I compensate for that by drinking slighly less water each day.

It's a trade off but I think it makes perfect sense after a few nights of not-sleeping directly on the ground under a miniture dyneema tarp.

About 12 days per gram.