I have camped with a uke but never a full size guitar. Not bike touring, but canoe. Guitars, esp. acoustic, are quite bulky.
I was thinking about getting a 'backpacker' guitar like this:
https://www.martinguitar.com/guitars/backpacker/
I recall seeing some cheaper Chinese knockoffs on the internet, too, although the Martin is not too dear.
Then an interesting older classical guitar came along and I blew all my guitar money on that.
Another option is finding an old solid body electric, and modifying the body to it's absolute minimum size so you basically only have a neck and the part of the body that holds the pickups to carry. You could probably cut off the part of the body that houses the dials and switches, and build those into a little box carried alongside, or just hard wire a single pickup to the jack, and use some type of miniature amp.
I have seen the collapsible guitars, and while they seem like a good idea I would expect keeping it in tune would be a PITA after reassembly. Either spend an hour reassembling and tuning, or spend that hour strumming a ukulele. Also, I would expect a lot of folks at campsites aren't going to be super stoked about the volume of a full size guitar, esp. at night.