You could dig them before first frost and cut off all the leaves and the stalk to around the height you want it to start out at next season. Store em in a cool dry basement. Although I found that I did need to sprinkle a small bit of water on them a few times over winter. Not much tho. I think if you DID leave them out till first frost they could be ok too though. You would of course get top kill, possibly down tot he ground, but as long as the corm does not freeze they should be Ok I would think. If the corm freezes, well, probably will turn to mush and be done for. good luck!

Depends on what you are doing with them after.

If they are going into a cool basement for storage
I would say it doesn't matter,if they are going in your family
room(for instance)you may want to save those nice leaves.

I dig up some of the stuff that's coming in so it has
time to adjust to "potted life" and to debug it...don't have
to dig them all up suddenly if the forecast changes etc....

I left my Elephant ear bulbs in until Dec last year,they are
protected by the warm ground and were fine.

In the case of my Ensete,I let it get frosted and then dig it up,
it's nice to see it out as long as possible,like after the leaves
are gone(-:

.......nothing under mid 20s though,you don't want the trunks
tissue damaged or it will rot over winter inside.

How cool of a basement do you think is cool enough for a basement. I recently finished my basement and instead of being 60F through the winter, it is now roughly 66-68 in the coolest parts. Is that too warm?

Yea,they would probably keep growing in those temps,
any chance the garage stays above freezing during winter?

Probably somewhere in the 50/60 range would be best...who knew...right?
Mine even grew little in the 50F temps last winter inside 0: