Next spring, instead of a large eyes, you will get a series of rings of much smaller plants, due to the main bud dying and the smaller side buds growing. To combat the effect of heat dormancy, continue watering the plant. You want to keep the root tips growing. I have shown how dicots are much more efficient at getting water with their netted roots, and at cooling with their branched veining. Many hostas are planted under maples and other trees that are expert water gatherers.
Competition is fierce and it is usually the monocot that loses.
Over time, the soil gets compacted, making it more difficult to hold water. Maple roots have been known to actually encircle hosta roots, looking for water. You should dig out and cut back those invasive roots, and amend the soil to keep your hostas healthy. H. sieboldiana types do not have a flush of growth in the fall. Do not fertilize them.