I don't quite follow what you mean by "Brideshead Revisited hangover" - from Wikipedia, it seems like it roughly means "nostalgia for the age of English aristocracy"?
That's about right. Think candlelit dinners with lots of claret, terribly clever undergraduates writing terribly clever 1500-word essays on their PPE course, the gentleman amateur.... Things that were great in the 19th century and have now become parodies of themselves.
I think that's an accurate portrayal of the "ivy league" type unis in the UK. They may not be what they once were, but they have a particular romanticism about them that people aspire to attend them.