"I am Canna, hear me roar."

Oh, wait a minute, wrong forum....

Here, we always grow them in the ground, but when I've dug some up for neighbors, for swaps, or to thin them or move some to another part of the garden, I've found big ole roots, too.

Maybe you could grow a cluster of them in something like a whiskey barrel next year?

Of course then you'd have to dig each one out separately for winter storage, but it might be a fun experiment.
Maybe bigger blooms? more blooms?
Have fun!