Updates:
I cut the original plant into four parts, and then after it had stabilized and calloused over I removed two of the four parts. All three pots were inadvertantly left in the cool greenhouse initially and experienced temperatures just above freezing. They were then moved into the main greenhouse (night time temperatures maintained at a minimum of 45F).
The quarter plant which had quickly established a new growth point now looks very much like a single young ensete plant, with a bit of the parent quarter leaves still sticking out the side. It wasn't convenient to dig it out of the banana collection, and it looks very typical of its type, so I didn't take a photo. I expect that as it warms up this plant will either grow very quickly on its oversized corm, or sprout some pups. I'm going to treat it like any normal young plant just to see what happens.
The two pieces that were left in the soil with the top of the corm above the soil line are shown here, and with a close up as well:
You can see all of the new growth points on the top and bottom in the closeup. The low humidity before they were moved into the greenhouse thickened the callous a bit, but the greenhouse itself runs 50-80% and I think that encourages the new growth points.
Finally, the piece which I buried deeper in new soil lost its parent leaves, but has much more developed growth buds. From a different angle and with some poking I count 7 separate growth points above the media so far. I expect some of these to not make it, or be absorbed by their neighbors, and new ones to show up.
