That doesn't mean I can't be disappointed by how something looks like it will turn out. All I know is that, in my eyes, Bethesda will lose a MASSIVE amount of kudos/respect points if we don't get the WHOLE island of Solstheim to explore.
First of all, OP, you have all the right to be pessimistic, considering how "misguided" we were on some details in Skyrim's trailer/demos. But I think is safe to say that Dragonborn is going to include all of Solstheim, since this island was actually small in size. To have it half the size would be just laziness. I wouldn't be surprise if the expansion size matches that of Shivering Isles.