Wow! I backpacked that route about 20 years ago, and spent 5 days hiking the distance! And they were long days of walking, too! Some days there were multiple 1000' passes to climb and descend. It's really remote back in there.
For a practice run of this magnitude, I think they should be able to carry more substantial survival gear than a trash bag. Yeah, it's better than nothing, but for 19 ounces of gear like I showed above, they could have a tarp shelter and an insulation layer under an actual waterproof breathable jacket. The 11 oz poncho-tarp Steve uses would be another great alternative to ride out a storm, but difficult to run with.
Ultra-marathon runners could learn a thing or two from ultralight or superultralight backpackers. Now if I could only learn to run that far...
