Re: Official statement on map sizes
Doesn't look that much larger. King's canyon is 2x2, so maybe this one is about 2.5 x 3 km.
Just measure it if you have nothing to do: land above refinery, put a ping below dome (mark the distance to your ping) - that's roughly max height, go to the E edge near refinery, put a ping on the west edge - that's roughly the max playable width.
I think it's probably 3x3, but horizontal part has much of sides unplayable(so would roughly be 2x more playable area than king's canyon).
P.S. If that's the case, then World's edge is still smaller than PubG's "tiny" Sanhok 😉.