I live in Atlanta, GA and bought an Esperanza last spring, which did not bloom until I put it in the garage about two weeks ago in preparation for the frost. It is a tree form in a pot. There is no light in the garage until I open the garage door which is only for a minute or two driving in and out. It now has a few blooms and buds on it. My plan was to let it go dormant for the winter and then bring it out in the spring; however, I am now wondering if it would be better to try to keep it in a sunny window inside and deal with the leaf drop. Or perhaps leave it in the garage and use a grow light. Any advice would be appreciated.
While esperanza, or yellow bells, is a very old and well known plant, the modern varieties in nurseries now have only been brought out in the last few years. There's not a lot of information on them. I couldn't find any tales of wintering over in a dormant state, so until someone tries it, I think the best idea would be to take yours indoors to a sunny spot, and treat it as a houseplant. I did find several references to using them as houseplants.
Regarding why it didn't start to flower until you took in inside, that's kind of strange. We do know that it's a young plant, and juvenile plants frequently behave in odd ways, so its weird flowering might be a case of youthful confusion. One idea does occur to me - perhaps the spot it was in wasn't receiving enough light to initiate flowering, then as foliage started to fall, more light hit the plant, so it quickly set about making flowers. At any rate, here's at article about these interesting plants, which I'm looking forward to many more people using. https://www.gardeningknowhow.com/ornamental/shrubs/esperanza/esperanza-plant.htm