I'm not sure with carpets, but the videos I see of the snake catchers in Australia sure make me think they get pretty large in the wild.
Carpets, specifically coastal carpets have adapted very well to human encroachment. It seems the areas around homes provide a host of prey opportunities be it wild animals, or domestic dogs and cats.
They certainly seem large when the snake catchers show up.
The most beautiful boa I've seen is wrapped around somebody's leg in Vin Russo's book.
Huge and solid as rock. It was a Suri I believe.
I don't expect my female coastal to get much larger, yet she surprised me this last year with a growth spurt at 6 years old and now she's 7.
She's not a predictable eater, I typically try once a month these days but she goes longer too.