Most varieties need 1" of water a week. I got a canna rhizome from a community xeriscape garden which I help maintain. As the name indicates, in that garden, it doesn't get watered and it does fine. However, in my yard, it did nothing, perhaps due to not enough sun. The one pictured above gets 6+ hours of sun and is watered 1"+ a week.
Most web sites say that the canna is not hardy below zone 8 and we are in zone 7b. The ones in the xeriscape garden overwinter nicely there. Even the one in our side lot overwintered, though it never grew much and didn't bloom. The one pictured above was put back in the new bed in December and obviously did well, though we had a mild winter.