I came across an old article in Persuasions where John Halperin argues that Chevening Park was a model for Rosings.
Rosings is described in Pride and Prejudice as being “well situated on rising ground” and “a handsome modern building,” which fits the account of Chevening Park given in Paterson’s Roads (1826); in Jane Austen’s day it would have been about 165 years old, but it had just undergone extensive renovation.
I googled it and found some old pictures.
The article is worth reading anyway. Although I have no opinion on Austen’s own personality, the author makes some good points about P&P. Read more at JASNA.