It's often difficult to decide how exactly to understand the geography of this series. Technically speaking, Ocarina of Time and Twilight Princess are both "canon" games, which means that they are both true to the intentions of the developers. However, it gets tricky when you interpret canon as "every facet of the game is exactly true." If you do choose to believe that is true, then you have to make a number of questionable rationalizations for how the maps change. For example...
• An entire mountain range (Snowpeak) grew out of nowhere since the events of Ocarina of Time.
• Zora river completely changed course.
• Zora's Fountain and Zora's Domain both moved... somehow.
• Massive ravines appeared in Hyrule Field. Meanwhile, the Gerudo Valley canyon has disappeared.
• Hyrule Field grew to about three times its original size.
And so on, and so forth. While some of these aren't so farfetched, trying to explain the location shift of the whole Zora area, and the expansion of an ice cavern into a mountain range is ludicrous.
Just compare these horribly marked maps of TP and Ocarina of Time - I tried to show analogous areas and the relative proximity of them with these marks. Obviously, I didn't include Zora's Domain in the marking, and you can see why:
(I found the original maps
here and
here.)
Even if you generously allow for some wiggle room between, say, the Gerudo Desert, Lake Hylia, and the woods, you can see that Zora's Domain has completely changed its location.
Because of how much certain areas have changed relative to each other, I think it's more helpful to adopt an attitude of "relative" canon as opposed to "absolute" canon.
What I mean by this, is that as the series develops and more and more games are released, you can't expect every fact to line up. There are some very good reasons for this:
• Technology limits how Hyrule moves from the developers' imaginations into the actual game. Because of technological advances between the games, Twilight Princess has a much more detailed and expansive map. I would argue that the Twilight Princess map is closer to canon than the Ocarina of Time map because the technology is better able to express the developers' vision for the game. Which brings me to the next point:
• Recency of the game. While I love Ocarina of Time, it was released over a decade ago. The developers' ideas about the series and the direction they want to go have shifted considerably in the past decade. This is a good thing - they are able to incorporate fresh ideas into their new games. Do we really want to be trapped in the exact Ocarina of Time map for all eternity? Simply put, I believe that in the case of Legend of Zelda, the canon of newer games trumps the canon of older games. If you want to debate this point, fine. But I think in the case of geography, this is especially true.
• Geography is less important to the developers than gameplay AND story. I really believe that the developers don't care about the minutiae of location as much as we do. It's more important to them to show off their new technology, tell a story, and most importantly, entertain the players. This requires that they are able to shift and adapt things, and not have everything set in stone from 13 years ago.
• The Legend of Zelda's status as a "Legend" allows for changes. Note that the timeline already, for better or worse, takes into account multiple possible outcomes and histories. In the same way, each game is part of a legend, in which the details may change, but the overall allegory of the story remains sound. The main elements of the legend - Zelda, Link, Ganondorf, The Triforce, the Three Goddesses - have remained more or less consistent while other things have shifted around them.
I am glad that when making Twilight Princess, Nintendo thought about using the Ocarina of Time map as a starting point. But I am also glad that they didn't treat the map as sacrosanct, and felt free to expand and develop it to the extent that they did. If the Zelda Wii-U game is as expansive as it seems like it is going to be, I expect another map that has ties to previous games but goes beyond them in order to create new gameplay and to more accurately portray Hyrule as it exists in the developers' imaginations.