One of my lady walking companions, Judy Armstrong is something of an expert in long distance walking with extreme lightweight equipment.
She is currently in training for her next year long adventure and, albeit on easy roads and trails, is working up to 60 miles walking a day. Not that she will do that everyday on her main walk, but it is how she trains. I know she passed the 53 miles in a day mark not long ago!
I ran a web site for her last effort, and whilst she changed her plans she still walked 4075 miles in 275 days in the French Alps: Most high up in the mountains. Oh, And during those days she did just under 1.3 million feet of vertical ascent.
Left hand panel on the Home page has a link to her Equipment Choice.
She has written one or more magazine articles in the UK about such walking with extreme lightweight gear, and if you go to the web site there is a CONTACT link, to get through to her.
I would add that she sure has to dumb down when she walks with me! I'm old, overweight and very slow.
But she is kind and understanding about that.