I figured out a rough estimate of the size of the fully zoomed out map that was shown in the video.

Each of these dots is one of the trees that we see in the valley that Link jumps into.

I measured the space between this U shaped body of water, and found that about 16 trees could fit into that space.

This is when the map is fully zoomed out. I circled where the U shaped river is. The space between the top of the U holds about 16 trees. On my laptop monitor this space was about 1/16th of an inch, which means that 1 inch of space on my monitor was equal to 256 trees.

I'm assuming that the trees are about 20 feet in diameter, but that's just a guess. If someone could better estimate the diameter of the tree then this could be much more accurate.

On my monitor, the zoomed out map had dimensions of roughly 5.5 x 4.5 inches. If you multiply each of these by the number of trees per inch, you get an 1408 x 1152 grid of trees.

When I multiply the number of trees by 20, I get that the map shows an area of 28160 x 23040 feet.

**This is equal to an area of 5.42 x 4.36 miles (8.7 x 7.1 Km).** That's equivalent to 23.6 square miles or 61.8 square kilometers.

These figures are probably off by a few hundred (or thousand) feet, but they give a good estimate of how truly huge the new Hyrule will be.