More background: I was by Barrett Lakes basin only twice. I am not "intimately" familiar with that area. Once went over Knapsack, Potluck, Cirque passes in a day. In 2014 stayed overnight.
Some more background: I was surprised by a Fall snow storm twice. Once on
Taboose Pass (click for a brief description of that event). Another time last year morning October 1st I aborted a climb of Turret Peak (planned to continue to Three Island Lake) when snow started falling from dark low clouds. Not much wind. Descended to trail by Piute Creek near east side of Turret Creek (
map). I wasn't sure if that was doable or I would get cliffed out. I didn't send OK from SPOT until I reached the trail (perhaps because typically it means to stop and wait for 20 min). Turning on tracking didn't cross my mind (I guess it would if terrain got more difficult). I was focused on getting to safety. Down, and then planned to go towards Pine Creek Pass. I didn't know how bad the storm was going to become. Morning 10/4 same trip, as a worse snow storm was starting, I was descending from Granite Pass to trailhead (hiked from Italy Pass the previous night, since I heard the forecast from a JMT hiker). Each time the thought was down and out.
Even if my (or Mr. Woodie's) initial back to safety plan was to go over Knapsack Pass, if I was getting too cold in the extreme weather in exposed terrain I might have to look for shelter urgently. Part way down Barrett Creek, perhaps to the trees, could look reasonable. Possibly even further down, if it looked not too hard.