The best way is to grow hibiscus in pots at least 10-12" across and then move those plants to a warm, bright location for the winter. It can be a heated greenhouse or a heated room in a house. There should be strong morning or afternoon sunlight coming in the windows in that room. Saucers should be used under the hibiscus and ample water given to the plants whenever they start to dry out. Half-strength fertilizer will help them get through the winter better. If all the above can be managed, not only will your hibiscus survive the winter, but they could reward you with many blooms during that time!