I just head about this in an email. It looks like the event will be rescheduled for 12 December 2.30-4.00 pm.

For further information best to contact  the RGS. Details: Telephone: 020 7591 3044 Email: showcase@rgs.org.

Related article:

Event – Patrick Leigh Fermor: An Appreciation by Alexander Maitland, FRGS