It'll be printed at 7x2 meters, i.e. @ 35 dpi (billboard resolution), which seemed fine to me. There's obviously much more detail, even if rendered 10 times as large, but I wouldn't be able to pay the electricity bill anymore
I could have added lots more little fences, more different people objects, crates, and other stuff, as the memory use wasn't even big (<6GB). I also could have painted in lots more items in post, but I have to move on to other projects (for a decent income).