This is something new I would try (or not?). Nudist beaches - done! Naked bike ride - done!
On a practical side: how comfy is it to hike naked? I mean, carrying a backpack and having no...

Oh, come on, let's see what songs and moves we pick when we get older ;)

The first few books that popped in my mind are:
1. Slaughterhouse-Five Kurt Vonnegut
2. Battle Royale Koushun Takami
3. Borne Jeff Vandemeer

Breathtaking beauty of the Caucasus!
What about ski passes and accommodation in Gudauri? Any tips on where to buy a package not to worry about cash on the way?