Maybe nobody's reading this forum at this time of year?

In the absence of a more expert reply from someone in a colder zone, I'll offer up what *I* would do if I were in a colder zone:

dig them up (before property owner changes mind or throws them away himself), cut off old stalks, put them in a dark place where they're not likely to freeze or get wet, & then plant them asap.

Best luck, & enjoy!

You might even want to start some indoors, for planting outdoors when all danger of frost is over. They do make nice house plants, if you have the room.

It's awfully early to start them indoors. I would dig them up, lay them out to dry out some (my preferred method is on cookie sheets on the dining room table where they get afternoon sun!), and pack them in peat moss or wood shavings and keep them in a cool but NOT FREEZING place for a couple of months.

I start my cannas in March here indoors for putting out during May. If you start too soon, they get lanky unless you have very bright light, plus they get very big very fast and you might run out of room before it's warm enough outside.