This isn't the full trilogy. Just the original production based on the first book. Whether they'll air the next two of the trilogy (To Play the King and The Final Cut), I have no idea. But it would make sense.
Even if you you miss the start, know that it's on for the next four hours, and well-worth watching if even for a few minutes to see the monumental performance by Ian Richardson, as 'Francis Urquhart.'
Am I suggesting you must see it? You might think that -- I couldn't possibly comment...