Yeah, don't go by "watering day" schedules. Check every single day. Those look like three gal pots, possibly with peat-based medium. If that's the case, plants that large in my tents in the same scenario require water every two days, if not sooner sometimes.
You've got the overall good health of the plant on your side, and the fact that it didn't get too bad. They'll bounce back quickly. Always water until slight runoff, then wait for the pot to dry out, and water again.