I've been trying to figure out the size of the map, and so I've taken a close look at the four levels of zoom seen in the latest video. Luckily most of the map is not obscured at each of the zoom levels, and so I've managed to take measurements between fixed points to come up with some (hopefully accurate) measurements.
My methodology was to first choose an arbitrary unit. I settled on the length of 10 trees (roughly), and I'll explain later why. Once I had this unit, I simply then measured the distance between two fixed points (the pink dots in the screens below) that were also visible on the map when it was zoomed out to the next level. I repeated this process for all four levels of zoom.
Bear in mind, I obviously had to correct the map images for perspective and distortion, so this wont be 100% accurate. Also, when going up a zoom level, detail is obviously lost and therefore it was slightly hard lining up the fixed points exactly.
Zoom level 4:
Zoom level 3:
Zoom level 2:
Zoom level 1:
So that gives us the map size of 84x100 units. OK, so why did I choose 10 tree lengths to represent one unit? Well, looking closely at the parts of the video where Link is riding through the small forest of trees, it appears that it takes Epona about 10 seconds to ride through 10 trees.
Based on this we can get an estimate for how long it'll take to traverse the map:
Time to traverse height of map: 84 units x 10 seconds = 840 seconds =
14 minutes.
Time to traverse width of map: 100 units x 10 seconds = 1000 seconds =
16.66 minutes.
This is assuming Epona can travel at full gallop constantly (AND that my estimate of 10 seconds for 10 trees is even correct). So let's assume Epona can't gallop constantly, and so she takes 15 seconds instead of 10 to cover 1 unit (10 tree lengths). The figures now look like this:
Time to traverse height of map:
21 minutes.
Time to traverse width of map:
25 minutes.
Further to working out the speed it takes to traverse the map, I also chose 10 tree lengths to equal 1 unit, because if we can come up with the diameter of 1 tree then in theory we can work out the size of the map!
Feel free to offer any improvements or corrections, I might be way off in my calculations!