This month (July 2016) BBC radio 4 extra is making "The Complete Smiley" available for the first time in quite a while (5 years or so?). They are available for listening on the BBC website for 29 days after the initial posting.

These are the stories featuring George Smiley, dramatized:

Call for the Dead
The Spy Who Came in from the Cold
The Looking Glass War
Tinker, Tailor, Soldier, Spy
The Honourable Schoolboy
Smiley's People
A Murder of Quality
The Secret Pilgrim

I haven't had a chance to listen to them yet, but I've got several of them queued up. The running times vary, depending on how the stories have been split... or not, as the case may be. These all appear to have the same actor playing George Smiley, which in BBC Radio productions usually is a sign that the same production team (and quality) remains constant across all the various productions. I enjoy the genre, and I appreciate the slow burn within the books I've read, so I am looking forward to listening.

I tend to keep up with the dramatizations that the BBC makes available online, and I haven't seen these in quite a while. It's also unusual that such a collection is made available more-or-less simultaneously. This is good if you want to binge, but it means they will become unavailable all at the same time.