I would buy more RAM tomorrow if it could give Ernie a bigger map to work on.
The current map is wonderful, but look at ( http://www.matrixgames.com/forums/tm.asp?m=3750186 ) for a map done for WITP:AE. Imagine playing GD1938 on such a map.
I thought about making mountains similar to these with the interior graphics mode. One thing that I like about it is that it can give a nice sense mountainous ridges. The problem though was that it does not look as if it is possible to "blend" them with other seasons. You can make the different graphics for the seasons to be the same terrain type so that they match in general, but there will be a hard edge at the hex boundary. Thus, there will be a sharp boundary between, say, summer and fall or fall and winter. With the exterior mode, I solved this problem by using borders. This actually happens for the urban hexes in my maps, but the contrast is not so stark, so you don't really notice the sharp boundary between the seasons.
I think the biggest issue with large maps is not really memory, since you can always get more, but the time between turns. The GoT map I made is ~ 100x150 with 14 regimes, and after say 15 turns or so the turns were taking about five minutes. I could upgrade my CPU, which would help, but ...