I measured them myself for someone previously. Hope this helps.
Basically max length behind the passenger seat.....all the way fwd and tilted fwd is 96". Towards the center it is about 97-98". Diagonally it is about 108".
Realistically...I sit with the driver's seat all the way back....and from the rear hatch to the back of my seat along the side is MAX 84". From the center of the hatch to the closest point on the center console is 85". Below are some photos that show my measurements behind the passenger seat.
It all comes down to seating position and the size of what you are moving. It is safe to say that no matter where you sit, you can get an object of about 80" in length in with all seats folded. I had a couple of 80" doors in the back no problem.
I moved a 4x8 sheet of ply cut in half to 24x96 behind the passenger seat.
With the seat all the way fwd and tilted fwd.
There's just over 96" along the side. The door will shut depending on how high/wide/long your material is.
Towards the middle you get even more length.
If you go diagonal you definitely get over 100" in length.