I would try to put myself in their shoes. I am sure they would love to come home to be with their pups instead of sitting in a cold crowded airport, but they have no choice in the matter. I believe it would be fair to charge your normal nightly rate. You should of course be compensated for your time and flexibility, but at the same time the owners could not have foreseen a winter storm that would delay their flight. Also, by being flexible and accommodating, you will most likely receive a stellar review and a loyal client for life.

If you were unable to watch their dogs longer, it would be best to ask the owners if they have an emergency contact that could possibly take over care or if they have a different sitter in the past they have used who might be available.

Good luck! I hope the weather clears up soon for the owners.