I live in Zone 5b near Denver. I have a canna obsession, but they generally can't survive in the ground over the winter here. So I over-winter them. I'm sort of lazy, so I leave them in larger plastic nursery pots (easier to move for me) that I wrap with bubble pack and cover with brown paper and put them in the garage. In the Spring (April), I bring them out and start putting them outside during the day, then drag them all back into the house overnight until it's warm enough for them to stay outside.

I try to put the plain nursery pots into prettier containers but that doesn't always happen as you will see below.

Here are some before/afters.

Before, photo taken on April 7

The plant in the center above today, it just started blooming. Hot pink.

This is the one on the far right in the before pic. It's red and has actually been blooming for about a month. The little one on the right was in the far left in the before pic. It's a dwarf variety with a peachy-pink flower.

And these two not pictured in the before photo but they were the same. They have yet to bloom.