This is the Utube that Andrew Bentz & Co did in April 2017.
They both have A LOT OF EXPERIENCE in this area (Bentz had record for fastest JMT unsupported at 3 d 10 hr 59 min). Looks idyllic, but conditions were very different than Lt Kraft faces. They had no precipitation it appears, terrific visibility, lots of packed snow, 2 of them to split carrying gear, and they bailed out once to Mammoth. They also ended in Tuolumne Meadows, not another 20 miles farther along at Mono Village, Twin Lakes where Lt Kraft intends to end his trip. And because of the snow packing, they weren't always breaking new tracks in fresh, heavy wet snow in blizzards as he would be doing
They did it in 9 days in what looks like perfect conditions.
So yeah, 15 miles a day in perfect conditions entirely possible
They didn't exactly follow the summer route as the snow cover allowed them to much more easily and quickly descend and ski through talus fields and lake basins.
So 20 miles a day even in perfect conditions sounds, very optimistic.
Surely he left a more detailed plan with bail out options with someone. Also unclear as to why he wouldn't take advantage of a PLB. (At least we haven't been told he had a PLB). Maybe something happened before he even activated it)
https://www.youtube.com/watch?v=ZojE9nhR88o
