My camellia is in a pot and has overwintered the past 5 years or so. I do increase the pot size every couple of years but it's very happy in a pot, we give it camellia feed granules in the spring. At we have a patio garden with gravel and slabs, nearly everything is in pots, including oleanders (a bit frosted this year but look fine now) and all my bulbs are sprouting again.