I always watch for our first hard frost, I'm in NY.. Mine are in pots so I have to cut them back and dig out the bulbs. I think your bulbs will be fine if you wait for the leaves to wither. I know it hurts me to have to cut off the gigantic leaves. Maybe others will have better advice for you.
Christine

The question is what's better for the plant, not what it can stand!
You could most likely leave the tubers in ground until December, and most would be just fine, but for how long? Wet and cold turns em to mush after a while but even if they survive its weaked them!
I personally let mine stay out until the leaves are gone but before the whole stem get frozen, then clean and dry them really good! I rarely lose any over winter, the best way IMO to overwinter is well established in a pot and left dry, under the right conditions I've stored bulbs 16+ months this way, just add water and in 2 weeks you have EE again, this technique will usually get even marble sized tubers thru winter, but not 16 months!
You should be fine as long as your storage technique is sound, that's the main thing!

Thanks so much! I usually overwinter my alocasia by cutting off all leaves and letting the tubers totally dry out before laying them in those low fruit boxes with the holes in them in my basement furnace room. There's no humidity there and I only lose a few that just dry out and crumble. It's the Colocasia that don't really have a corm to dig out that I don't know what to do with. I've read here to just put the roots in water. Seems like a long time to do that without them turning to mush. Do you need light?

Colocasia don't normally go dormant. If they're stressed they can end up losing all their leaves, effectively a forced dormancy. Dry/cold can cause that stress. If they're in water they'll keep trying to grow. But if the water's too cold they'll rot. It all depends on how you treat them as to whether they'll turn to mush or keep growing. And if you store them dry, put a damp cloth in with them so they don't get 100% dry and keep them cool, not cold. They'll only need light if you keep them growing.