I know that it will not be possible to have my house covered with color, but I am still trying. I planted one of the indoor plants on the south side of the house last summer. When winter came, I covered the whole plant with foamboard. The plant appeared to die, but it did not. The protective cover kept the rootball alive and now it is leafing out!!! Let's see how much growth it will put on this spring and summer.
Unless global warming keeps our winter temps above freezing next winter, we will only get a limited amount of growth before the top dies back. So, the color will be kept to a small amount.
Even if we had a tropical climate, there is not enough time left in this world for the bougainvillea to get very large. Jesus is coming very soon!! Then, by God's grace we shall all enjoy the beauty of heaven, then the New Earth!!!