Not bigger, but....

[Kyrre]

See attached, I think it would be possible, however, coding required for aeroplanes mainly, a bit for boats, would make for interesting games, especially if a random generator is possible for that in some way.

[Kyrre]

It would have the potential to Spell out "N-ice" in bloated joined up text to make up a map, which can then be used as a template for the random generator, not forcing the generator to make a map itself.

[iSoSyS]

Not feasible. Void titles (black in the map) can only appear at the edges. It is enforced in the code:

Code: (tile_map.h:130) [Select]

assert(IsInnerTile(tile) == (type != MP_VOID));

and we can't change code that affects client side behavior.