My update is, that my project failed. I started laying out the PVC and the area of the pen was just too big and the PVC bowed. But, with that said, I did accomplish another project. Since I can't have a lid on the large pen, I reconstructed a new, beefer night pen.
I bought a 12-foot by 1-foot tall by two-inch thick section of pressure-treated wood and cut it into four sections and built a new pen, complete with new lid. This thing is so tough compared to the little temporary pen I made out of scrap wood. It came out very nicely. My plan is to hibernate the boxies in it so I can know where they are and not have to worry about predators. Here's a picture of how it came out. You can also see the bench I built to the right. It's getting a lot of use; I can sit and watch the Eastern juvies or watch my hummingbird/butterfly garden to the left of the night pen.



