I've put together a pretty big list of features from my earlier maps and notes about the three regions that are now canonically included in DH5. Here's where I'm worried that I might have a problem.
Unless I draw quite small, I may have already come up with more details than I need. Should I, then, actually do three separate maps? Or should I reduce the detail and not show all of these features? Or should I have more than one map for more than one purpose?
If you watch map-drawing tutorials on Youtube, you probably only come across a handful of channels that do it, so you'll probably see all of them. Esper the Bard has a concept of four "levels" of map, and his #2 and #3 would be the ones in play here. He suggests that #2 is the one that you use the most, and it's a "kindgom" style map. In my opinion, it's a really big kingdom, looking at this example, as in scale it seems quite similar to the famous Middle-earth map, which of course includes many kingdoms and is about the size of Western Europe, give or take a bit. But, I agree that that's a good scale, I'm just not 100% that I can squeeze all of the items I have on a map of that scale drawn on an 8 ½" x 11" sheet of paper. Maybe I can. After all, Christopher Tolkien's map has a fair number of features, and it was printed in a mass market paperback! Although his original was drawn, obviously, on a much larger source.
One possibility is that I have at least one map that shows all three of the regions and their relationship to each other, and then maybe three separate maps for each region that show more detail. Another possibility is that I try to squeeze as much as I can in and don't worry too much about it. To be honest, I don't really know how feasible that really is. Maybe I don't have as much as I think I have. But maybe I accept that I'm trying to make Esper's map #2, not a map #3, which is a much more detailed regional guide, more like the kind that would be included in a module, showing a lot more very specific locations. Let me give an example with some map image files that I didn't have too hard a time finding with bing image search.
This is Nentir Vale, the map that was included in the 4e DMG, and which is already a smallish area, but it's the closest thing to a setting map that 4e really gave us. It's a really nice piece of map artwork, and I've actually picked up a few techniques here and there by imitating what cartographer Mike Schley did with this map, although look at that later at your own leisure. First, just pull it up and check out the bottom right 15% or so of the map, where there's a big bight in the forest, a road and a dot labeled Harkenwold. Even if you open the image in a new window and zoom to actual full resolution image size, you'll see that there isn't a ton of detail around that area
This next image is a (poor) scan of some kind from the module Reavers of Harkenwold. It's the same area, and honestly it shows it at about the same resolution (although it's not even close to being the original source file for the image, no doubt) and yet, we've added all kinds of details. That's probably appropriate, because being that it's a module, it needs to show all kinds of areas that your PCs would visit, including some poor widow's house, a camp in the woods, etc. But some of the stuff is more permanent and notable; there's a bunch more labeled villages, hamlets, steadings, paths, and the hills to the east that are not labeled on the first map are now called the Briar Hills. In fact, it actually changes some things; the place labeled Harkenwold on the bigger map is now a village or small town named Harken; one of many in the whole forest bight region, and now Harkenwold is a regional label rather than a town label. The new paths aren't just additions, too—there's even some minor differences between what's shown on one map vs the other.
Now, I'm not trying to say that one or the other map "got it wrong", merely that the maps serve two different purposes, one being a regional overview, and one being a usable tool to adventure in a smaller, more constrained specific area.
I think that mentally I sometimes struggle with the difference between the two; I want my maps to be able to serve both purposes at the same time, and it's not likely that it will. One does, however, have to accept that in a regional overview maps, that there will be details "on the ground" that the map doesn't always show.
Anyway, I don't really know how big of a problem I have until I start trying to draw it. My original Hill Country and Timischburg maps were each drawn on the same size sheet of paper that I'm now attempting to use to show both of them together, plus a third region yet. It may be that I have too much material for the map size that I'm trying to draw. Or, it tmay be that I don't. I guess I don't really know for sure until I start putting together the sketch-draft version of it and see how much real estate I really need to get everything in.
As a quick aside, Harkenwold sounds more German than English, especially the name Harken, but The Wold is an area you might find on the Middle-earth map if you look carefully at the greater region of Rohan. A wold or wolds is a word used in parts of northern England to refer to unforested open country; grassy hills, a plateau, etc. Yorkshire and Lincolnshire is where you're most likely to hear it, and it's very much an Anglo-Saxon English word. It is, however, closely related to weald and wald, cognates for each other in Old English and German respectively, which curiously means forested area, i.e, the Schwarzwald or Black Forest. Anyway, I'm a fan of Anglo-Saxon linguistics and archaic or unusual words, so I've got to give the designers at WotC some credit for finding and seizing on this word. It's not that it's hard; like I said, it's right there on Tolkien's Middle-earth map, for crying out loud, but I don't see many people use it. The Hill Country has done so as well; there's a region called the Goldenwolds that is an upland region with tall, golden prairie grasses where buffalo, tarpans and other animals graze.