Here's the map I showed before (for comparison):
And here's what I've done with Hyrule Field:
There's no ground detail. Final trees won't have gray parts. For now I'm using the hollow tree entrance graphics for trees that you burn with a candle; this won't work for the burnable trees on the north side of a tree cluster (south of Level 1 for example), and you can see that I had to relocate the burnable tree on the northernmost screen on the far right of Hyrule Field so it could be approached from the south. Burnable trees might need to be reimagined; we'll see.
Enlarging the map really helps to use MC's large tree graphics in the same spaces that Z1 does without filling every screen so Link has no ground space to maneuver. Trying to keep large open spaces for enemy combat was a high priority for me. I added a generous amount of shallow water around the edge of the large pond to help keep space open for movement. And widened some paths between tree clusters (doubly important if I'm using MC sized Moblins).
It doesn't look like it, but trying to keep the trees in roughly the same places as Z1 without causing screen edge errors was a very difficult design challenge* and gave me a lot of headaches having to rework screens multiple times.
*hence the gray parts of the trees (colored parts are solid)
The fairy fountain was a fun design, hiding the fountain in a mini-maze and making a large "Z" for Zelda on the map.
There's clearly some more work that can be done on this, I'm not too sure about the rocks for instance; but I'm blocking in the big important stuff to give you a rough idea what I'm doing with this concept. Trying to start by staying as true to Z1 as possible and only reimagining areas that become problematic. Reworking things for purely aesthetic reasons can be done later, once the basics are ironed out.