Let's take a look at the first real-life videos presenting the 7-seat Tesla Model Y.
The first two videos, from YeLloE 1213, demonstrates shortly getting in and out of the third row:
There is not a lot of space, but as we can see, it's possible to use those seats not only by kids, but also by shorter adults, although probably just for short trips.
Another improvised video, by jasonchaaang, is longer and shows more things. According to the description, the seats should be comfortable for someone 5'5" or shorter.
"I’m 5’7” my head pretty much touched the roof, but I could make it work / slouch a bit for a shorter trip.
There was surprisingly enough leg room.
Also the second row could slide into 3 settings.
My mom is 5’3”. Here’s another video showing my mom in backseat at 30 second mark: https://twitter.com/jasonchaaang/stat...
As people have pointed out, I believe there is an arm rest in the actual seat (you don’t have to fold middle seat down)."
The cost of the third-row option is $3,000 in the U.S.
We will try to update this post if new, more detailed videos appear.