Well I checked out the War in the Pacific: AE map and its only about 270x200 hexes...
The scale of WiTP:AE is 40 nautical miles (46 statute miles, 74 kilometres) per hex. At a map size of 270 x 200 hexes, that equals 10,800 nmi (12,429 mi, 20,002 km) by 8,000 nmi (9,206 mi, 14,816 km).
To put that into perspective, the Earth's circumference at the equator is about 21,638 nmi (24,901 mi, 40,074 km). The circumference at 30º latitude N/S is about 18,739 nmi (21,565 mi, 34,705 km), while the circumference at 50º latitude N/S is about 13,909 nmi (16,006 mi, 25,759 km).
To include a sea route to Murmansk or Archangel, and a sea route past Cape Horn, this would mean a global map stretching from a latitude of about 75º N to 60º S, a distance of about 8,087 nmi (9,307 mi, 14,978 km).