After looking at the facts that:
1. There is a portal in Konoha that sends you near the Toad Mountain
2. The Toad Mountain has a separate atmosphere from the Naruto world
3. There are different dimensions in the Naruto world, which are conected
4. There's a path that leads to the Toad Mountain that you can walk on
5. Sasuke's Hawk wasn't affected
I concluded that the most reasonable explanation is this, as it incorporates all of these facts and is logical:
Summoning Animals live in a different dimension than the world Naruto lives, hence why the hawk wasn't affected by Infinite Tsukiyomi. They are connected by portals, such as the one that leads from Konoha to the dimension the Toad Mountain is located in, but not directly to the mountain itself. The route that was mentioned that takes 30 days is a maze that leads to a portal that takes you directly to the mountain, unlike the previous portal, and is located in a maze because it leads directly to the mountain, and not just the dimension they are in.