There is something of 12 hour rule for recovery from the drying outof plants, at least in pots. If you rewater carefully within the first 12 hours, you will get relatively little damage, with damage mostly to the growing tips and some leaf drop. In the second 12 hours, you are likely to lose half of the plant. In the third 12 hours, you will likely either kill the plant or will have it survive after a long recovery, resprouting from near the base.

Don't cut back until you have seen where the recovery sprouting is originating. You can tell if a stem is dead if it has totally dried out a week after shock and is brittle, and if the cambium (the active layer under the bark) is no longer green, but has turned tan in color. Break off a short section of stem, and scrape off the bark with your fingernail or a pocket knife.

This advice varies a bit depending on the nature of your plant, the soil, and the health of the root system.