wpegg: I think you forget how small a floppy disk was. 1.45MB, with so much other stuff to include. Compare that to the 650MB that awaited us in CDs. Back then things had to be seriously trimmed down, a map contains images, they were big old things as we didn't have the compression tech back then. They'd probably be .bmp in some form.
EDIT: Thinking about it, there wouldn't be any new images on the map, as the terrain was already separate. Still, there was very little space to ration out.
I grew up with floppy games. Contrary to what it may seem now, 1.45MB could fit a lot. We did have very good compression tech back then (check for example the Run Length Encoding used in pcx file format among others). And they were only 8 or 16 bit images anyway.
That aside, the biggest space hogging was sounds, then images, none of which would be included in the map. At most, the inclusion of Germany map would include 1 more additional floppy, a small price to pay for doubling the amount of maps.
EDIT:
Just as an example, Prince of Persia, which had 12 level fitted on 500kB. Wolfenstein 3D (6 episodes) was one floppy. Surely an additional Germany map would not need more.