Camillia japonica is only hardy to USDA zone 7 so it will never want to a freeze or even frost. We are zone 5 here in the Capital Region. You’ll have to grow them in containers and move them inside to a sunny, warm place in the house. Since they are large plants, this will take up a good bit of space. HERE’S a link to an article that talks about growing them in containers. I was they were winter hardy here but, if they were, you’d see them everywhere.