My baby was also so big he had to wear 0-3 sleep sacks in the hospital because he was so big he kept busting out of his swaddle & getting cold. DH had to run home to get him more clothes.
I didn't buy anything specific, but I picked out a pretty sleeper for her to wear. It turns out it was wayyyy too big for her. I only bought 0-3 mos clothes, but she needed NB so we had to go out and buy her a few outfits. She was also born in winter and was wrapped up in blankets and bundle me so the outfit wasn't really in pictures anyway.