If we look back to Jane Austen's Pride and Prejudice we can see that there were of course communities of enormous properties held by the wealthiest landowners, each topped with an impressive manor and people working the land for them too. But where exactly in England were these manors and farms? I can imagine somewhere closer to Middlesex rather than completely out in the Midlands of England.
Also we know of course that many had big mansions in the downtown and outskirts of London, such as the Duke of Wellington's own Apsley House, so I can imagine suburbs of the rich existed in certain areas too. Which were they and what are they now?
The Large country houses were spread out across the country, a decent cross section of these houses still survive, maintained by the National Trust.
For example, you may have read that Mr D'Arcy's house is in Derbyshire, while Seaton Delaval is in Northumberland, and by no stretch is it a mean little dwelling
There were also up-market suburbs, for example Bath's Royal Crescent, which remains exceedingly up-market. Places like Knightsbridge were also favoured, being close to Court, and again they remain extremely expensive areas.
I don't have a lot of time to go into this right now but /u/jonewer has it pretty much spot on saying that houses were spread out across the country. However, the amount of time that the owners - particularly the man of the house - spent living on 'the Estate' was fairly low.
Take Normanby Hall and it's family the Sheffields, who IMO were one of the main influences for the series 'Downton Abbey', and where the current first lady Samantha Cameron grew up. It's slightly after the Napoleonic period, but the family would only reside at the hall for around 5 months a year. The rest of the time would be spent in London attending to other business, whether that be managing income streams or socialising - The 'Coming out season' in Spring was (and still is if you read society magazines or the Daily Mail) the most importnt time of the year, with many of the big events that one had to be seen at being based in London or the Home Counties.
So technically, they mostly resided in Manor houses spread up and down the nation, but realistically most spent more time in London. The 'family home' was seen much more as a place to bring up kids, retire to and cement authority over your position in society.