I thought it was brilliant and agree that it could have been extended to more episodes. I think the Beeb underestimate the staying power of it's audience.
I believe posh upper crust women at that time didn't venture out much in inclement weather which may explain the flimsy dresses to a certain extent, but the tiny shawls they drape around themselves are far too small, I understood they were much, much larger and cosier for everyday use. Also long gloves and thick stockings would have been worn which makes a big difference.