Now why on earth would i want to walk 1000k with no resupply ! I'd love to be capable of doing it cross country living of my "bushcraft skills" but frankly there is NO chance of that happening. I don't have the skills to provide all of my food yet.
I do admire the ultralight idea, and apply parts of it too bushcraft - For me its a good point to aim for - as I know i will fall short (and put the axe in..) I have cut the handle of my toothbrush and razor down, ditched my wash bag in favour of a nylon "prog bag"...no stuff sac for the sleeping bag, no tent -tarp instead, ligher weight clothes and only one change... The biggest difference to me was changing to a smaller rucsack so i couldn't fit it all in - hence can't carry a load of extra kit (I find 35l ideal).
Water can generaly be precured and purified, so I carry less. But irefuse to live off dehydrated food, so this adds a bulk of weight to my pack Still light enough for everthing I undertake ATM.
Cheers
Rich