How about - careful, very outlandish idea follows! - if Bloferhauser was interned in a secret space station in orbit? And if Bond had to get him out to save Madeleine?
A British secret space station? We couldn't afford it - we had to get "private benefactors" (SPECTRE as it turned out!) to pay for that Centre for National Security in the movie.
But Blofeld will be held somewhere secret. There will be no media show trial, not least because of what might emerge - such as, as Bond points out in the movie, SPECTRE's intelligence chief and the UK's head of the Centre for National Security being the same person, the unloveable Max Denbigh.
Blofeld will be held somewhere secret - The Falklands, as others have mentioned, would be a good idea - and he'll escape and make for a bolt hole where he think no one will think of looking - as he said himself "you came across me so many times and yet you never saw me." And from there he'll either try to reconstitute SPECTRE or order something to happen which will once more cause Bond pain - leading to a final confrontation in which only one of the two - Bond or Blofeld - will emerge alive.