We wanted to go to Caldron Lake, but the bridge that reportedly should have been at 5.4 km was not there--either washed out or removed. So therefore the disappointment. We scrambled to Peyto Glacier instead but did not have the time to go to Caldron Lake from there--it would have added about 4 km just to get to the lake and back and at least 1.5-2 hours to the trip (with some exploration around the lake), making it a a very long day. We ran out of time. The Peyto Glacier trip took my husband and me 6.5 hours, and we moved pretty briskly. The terrain along the river and approaching the glacier is not easy.
That said, Peyto Glacier is a worthwhile destination in itself--but we really wanted to see Caldron Lake!