I just accomplished this route. It took a little sleuthing, and a little bit of hope. The result was well worth the effort.
Having started the day below Shadow Lake, I topped Texas Pass, dropped into the Cirque of the Towers, and climbed Jackass Pass, wandered down to Big Sandy Lake, where I became a little unsure of attempting this route. However, nothing ventured, nothing gained.
I left Big Sandy Lake at 4pm and arrived in Fish Creek Park and the Fremont trail at 7:30pm.
If you are heading this way and want to avoid the multitude of people and wandering trails around the Big Sandy lodge area contact me via PM and I'll fill you in. (I'd rather not post the details for general consumption, but am more than willing to share with those headed that way.)