A buddy and I just day-hiked Langley last Wednesday. We started at 8 am and returned at 5 pm. The stats from Strava are 22 miles RT and about 5600' elevation gain. We started and finished in the south parking lot (Cottonwood Pass trail head where we were camping) so we probably did a little extra mileage compared to the Cottonwood Lakes trailhead. If you have decent fitness you don't have to do a real early alpine start for this hike. We caught up to some guys from Minnesota who also had their Whitney permits cancelled. They had left at 3 am and said they found the climb to be pretty grueling, but they had come straight from sea level. As stated above, it's almost 2k less total climbing than Whitney but you are still climbing to 14k!
We climbed Old Army Pass with about 25-30' of soft snow near the top. There is a decent boot track through it so no crampons of microspikes required.
When we left Thursday morning the Whitney Portal road was still closed at the Horseshoe Meadow Road turn-off. Helicopters where still working the fire scene. The day before our Langley hike two DC-10 slurry bombers flew directly over Horseshoe Meadows readying to drop fire retardant on the Inyo Creek fire, as was a giant Chinook helicopter a little later.
As earlier stated, NO permit required for a day hike....have fun and be safe out there!