I'm also curious to see if any good ideas pop up in response to your question. Given the space and weight penalty, I've pretty much given up lugging waders along for serious backpacking trips. I wet wade, and it's generally ok until I get over mid-thigh! To be honest, I usually leave the traditional rod & reel at home too (in favor of a tenkara set up) if I'm logging a lot of miles and vertical. Have you looked at Chota Hippies - a little more packable than most options, but you still can't go waist deep.