Longwoods Tropicals

You should have no problem overwintering the basjoos outside. I planted one in a garden bed mid September last year, and it only had maybe a monththe ground before the hard freeze, yet it lived and with minimal protection, with maybe a foot of leaves and no tarp. My main mat that has dozens of plants in it gets about 4 feet of dried leaves and a tarp. I had weeks at a time last winter where the temp didn't reach 20f and several days of -5f for the high. The Zebrina on the other hand might not be a good candidate, but having said that if you have more than a couple plants I for one would be interested to see you try to overwinter one. If you decide to do so I would cut it down to 6 inches and use at least 3 feet of insulation (leaves grass, straw, whatever, your choice) and make sure the insulation surrounds the Pstem a minimum of 4 feet, then just cover it up with a tarp to keep moisture out.

Also I have accidentally left both colacasia and alocasia out in the basjoo mat and had them come back early in the spring, now mind you they were just small little pups that emerged from some little chunk of corm left in the garden. I usually pot them up and take indoors with the rest of the mobile jungle. Even large ones can be potted up and be happy indoors (one large one flowered for me this summer and it's still growing nice big leaves now that it's potted in a 10 inch nursery pot), just mist often, like you would bananas.

Regards Harold