Two really big flaws with this plan (can you guess what they are?). 1] The moon moves quickly, and in 30 minutes, it was totally out of the field of view. All of my photos were black frames! It moved up and to the right... but at a much faster rate than I realized!! 2] The lunar eclipse was really significant with regard to blocking out the moonlight (it's with difficulty I admit this didn't cross my mind ahead of time!). The exposure changed so dramatically that, even if the moon had stayed in my viewfinder, it would have been much to dim to register. Live and learn, right?
What to do? Try it again! The next night (4/15/2014) was a full moon with a moonrise scheduled for about 8 PM. No eclipse, so exposure won't change. Instead of 30 minute intervals between shots (which was way too long), let's try 5 minutes. Here's a shot with the 400mm lens and cropped to make it look really big. What a beauty!
OK, that's more like it. Shooting at 5 minute intervals with a 200mm lens, I was able to capture about 7.5 moon shots before it disappeared off my viewfinder.