We went on our first tour of the interior today. Some areas were much bigger than I thought and some felt smaller, but since there aren't any real walls yet, it was hard to tell. My photos of the interior didn't turn out very well, but here is a better image of the front entry area. Since there are people in this one, you can probably get a better feel for the scale for the space.
This image is pretty dark, so hopefully you can make it out...
Each of the four rear windows looks to be about 5 feet across and 4 feet high.