Very nice BG. Do they really over take a garden? That's what I've been told about canna. I think they are so pretty, but I have been afraid to have them because I didn't want them to over take my garden.
They don't take over a garden nearly like mint or a reseeding annual. The rhizomes will become larger and send up off-shoots as they do. But like Iris, Glads, etc, you dig them up about every other year and divide them. The extras you can give away or use them to create new beds. Where you are they will do best in a large pot that can be moved inside in winter since they are tropical and will not overwinter well. You can plant them in the ground but will need to dig them up before frost as they are likely to rot during winter weather like you have. Being in pots or dug up every fall will keep them from taking up more space than you want them to have.
I love white flowers...I always have some in my garden. I haven't had cannas for years but I found some tubers on sale so I put them in pots . I have never seen white ones..maybe next year for me..
