My LR3 didn't have the back seats, but I have helped others remove them. It's VERY easy, just a couple of bolts across the bars that the seats mount to. There is a fair amount of room there, especially if you build up the footwell in front of the seat to be flat with the rest of the cargo area. My middle seats are different than most normal LR3's, but you sorta can see the open area below the cargo area that would be the footwell for the rear seats in this photo:
With a platform built up over the rear seat area (or use the OEM plywood panel ordered through a Dealer), there is a fairly generous amount of room, even with middle seats intact, allowing room for 5 AND a sizable amount of cargo:
Middle seats down:
Middle seats up:
All this fits inside, even with the middle seats up and two kids sitting in them: