We did this as a two car day hike. Our route started from the Rattlesnake Trailhead in Cedar Breaks and then down through Ashdown Gorge finishing on Highway 14. It was cold in the morning starting above 10,000 feet so walking in the water wasn't bad down lower in the warmer areas of the gorge.
Left at 8:05 a.m. Fortunately the sky remained clear all day. Was 55 degrees F in the morning but once I got going, did not feel cold at all. Was back by 12:50 p.m. Not a single person around.