Well done, Cameron. Just so you know, you can't kill a Canna. Plant them somewhere else and they will bloom into November as long as you give 'em water.
Give the nanner a big dose of fert - couple of handfuls of timed release pellets should carry it into winter - and make sure it gets watered every day until the weather gets cold. Since you disturbed the soil digging up the Cannas, it might be susceptible to drying out until the soil compacts again. In fact, I'd be inclined to give it a bag of Black Cow or something as a 'treat' - you really can't over feed or over water bananas. They make a huge matted root system underground, and if they're happy they'll jump up, and make pups and generally make a really nice clump of big lush plants.
Keep us posted how it goes?
