I just got an email back from Jay Tummelson from Rio Grande Games. His answers indicate two things:
1. The cabin is a double cabin with spaces for six animals/provisions. The Wood Worm doesn't count as one of these animals.
2. You cannot create an illegal placement by combining cabins. If your combination would result in a cabin that could not exist then you cannot play the Wood Worm. Therefore you cannot combine a hot and cold cabin, nor can you have any other conflicts between provisions/herbivores/omnivores/carnivores.
Cool, thanks! That's actually how I was planning on playing the wood worm, and just using a hunch as justification. But it's great to get a confirmation from Jay. Thanks again!