Miyazaki is a liar. Shadow of the Erdtree is more than half the size of Elden Ring. It is a massive expansion that shatters expectations, and I've played 65 hours of it and am still discovering new places and items as of last night.
The map of Shadow of the Erdtree is better designed than the base Elden Ring. Its smaller size means various gorgeous and nightmarish areas interlock and loop within, over and under each other like a massive Zelda/Souls dungeon across a continent.
One boss in "Shadow of the Erdtree" took me 4 days to kill, longer than my previous FromSoft boss record of 3 days to kill Malenia and Isshin. It might be the hardest fight ever conceived. When I finally beat it, my body was literally trembling.