If your balcony, and the pots, are open to the fall and winter rains, the hostas would benefit from being moved late in the fall against a wall, out of the rain, to avoid their becoming waterlogged and rotting. If the balcony is covered, water potted plants minimally through the winter, just enough to keep the soil from drying out. Most hostas do well in pots over four or five years as long as they are kept adequately watered in dry weather and not over-watered, or left out in the rain all winter. Avoid directing water onto the crown of the plant. Water under the leaf canopy and around the pot rim. Watering too often, or on top of the crown, can promote crown rot.