I think we are going a bit off topic ... and we should stop somewhere. But before I'd like to comment on Bruce's and Des' posts and write down my latest thoughts.
@BruceBanner
The idea of your technique I know from Pseudo HDR technique. The strength is that you only use one shot. So no problem with movement in the scenery and you can opitmize the use of all sensor data. It helps. But I think, unfortunately, that this doesn't suffice the scenery Des describes.
@Des
I'd say in your scenery the already very good sensor DR is exceeded by a significant amount. So much that you can't create the shot you'd like to geet. So single shot even using Bruce's / Pseudo HDR won't help. I also did moon shots in the past. One learning was ... it is done best in daytime / nighttime transition phase. Then you can get details of the moon and environment much easier cause the contrast isn't that huge. But what could we do in your special the scenery?
My thoughts apart from what I said about using GND filters lead to the conclusion that you might use multiple exposure to cover a very wide dynamic range in a special way. I'll describe my thoughts and results from simple experiments in more detail step by step. Camera used: Pentax KP.
Basic Settings
Since M program is best for nighttime photography we choose this program plus live view showing the histogram. Since we are longing for best image quality and need do some post processing we work with raw files.
The moon moves much faster than we might think. So multiple exposures have to be done quick. Let me recommend HDR mode for this. Later you'll understand why. To fix some basic parameters we set an appropriate aperture, maybe f/8 or f/11, and ISO to a value that's appropriate for the lighting of the scenery and targeted exposure time.
HDR mode gives us three exposures. One baseline "0" exposure and two using plus and minus exposure offset. To get the broadest EV spread, set +/-3EV bracketing in the corresponding HDR Capture menue of your camera. The three exposures are stored in one raw container file, pef or dng. I always choose dng.
The cameras special HDR mode isn't that important since we will do our own HDR processing or blending based on raw files. The camera generatet jpg file isn't important to us. So we can simply set HDR automatic.
What's the next step?
Determining HDR "baseline exposure"
Now we have to determine the baseline exposure time "0" for the HDR capture. It's the one when we subtract 3 ev-stops the moon shows the detail you wish to get. In this exposure nealy everything else will drown in dark tones. How can we determine this exposure time?
Remember? We use M program and liveview. Using the front dial we reduce exposure time exposure time step by step. This doesn't work with manual lenses. So please use an "automatic" lens. With every step (shorter exposure time chosen) live view gets darker. At some point you'll realize detail in the moon. Reduce exposure time further until you see the details you'd like to see in your picture. That should be near ETTR (exposure to the right) in the histogram. Now something unexpected ...
M program - something unexpected in HDR mode
While experimenting today, I discovered something really convenient. Usually M mode doesn't work with ev compensation settings. But, hey - in HDR mode it does! Amazing, really cool! So we now simply can go into compensation adjustment and dial in a compensation of +3ev. That's easy because we are supported by the ev compensaion scale to do it. The baseline exposure time now is set. Exposures will be 0, -3, +3.
Dynamic Range covered
Now we trigger the shot and get the raw file containing three raw images bracketed. They cover an extreme wide dynamic range using ETTR (exposure to the right) technique. Example: if we say the sensor is able to cover a DR of 13ev we theoretically get 13ev + 6 ev = 19ev! That's our playground in post processing. Cool, isn't it?
PDCU HDR split (also see
https://www.pentaxforums.com/articles/photo-articles/pentax-dcu5-hdr-merging.html)
What to do next? In PDCU (Pentax Digital Camera Utility) we split the original raw container into three raw files. The filenames show postfixes _1, _2 and _3. I can't imagine to get better base data to work out my image vision. To get there we now can use specialized HDR software or layering and blending techniques. Another opportunity to experiment a lot ...