Yes!  But, as you have already figured out, it would be a prohibitive amount of work.  Gterl and I worked together on developing a Spanish Civil War map, and learned lots of useful stuff before we had to set it aside.  Gterl proved that 1024 tile art runs on a modern computer with no performance penalty - his excellent Italian Front map uses 512 tile art.  It was also possible to use 2048 art in a few special locations, such as airfields, with no impact on frame rates. 
  
We also determined that most TW game maps are too large when compared to the amount of time/labor available to make the map.  Gterl's Italian map is the maximum size for one guy to construct by himself - anything larger requires a team effort, or a reduction in detail.  I've considered making a 1940-41 map for Greece, but it would have to be very small.  As you pointed out: "long and hard to make."  Too big a map would guarantee it would never get finished.  
  
OTOH, a couple of small maps, using the same art and models but different terrain, is feasible.  Perhaps one small map for 1917-18 and a second small map for 1940-41?  Any ideas? 
  
Shots below give a feel for what was a very interesting time and place.  Biplanes and tri-motors!