I have many plants that were prepared for winter storage that have bloomed in the greenhouse where they recieved no water all winter. I would do as you said and let it go dormant rather than feeding and watering like it was still growing. Some water over the winter would help maybe save your inflo. Good luck.
Jerry

Marion, I stop fertilizing & watering plants that I will make go dormant. If you want to keep it growing in the fall / winter, you can continue to water (stop fertilizing also) but give as much light as possible by supplementing the natural with artificial means (12-14 hours per day). If you do this your inflo will continue to develop and bloom. Remember that white flies and other insects will create problems unless you treat periodically and use a fan to keep air moving.

Thank you both for the advice. What I have for light is a south facing bay window. i will put the Plumeria in the center. I'd really like to figure out a way to add artificial light for the 12-14 hours. I'd like that inflo to survive! Thank you for the warning on insects. I will keep an eye on them and treat if necessary. After 4 years, I would really like to see this plant bloom. I only have the one plant. It was a gift from my son.