Our clerk, Gisela, has confirmed, contrary to my comment yesterday:
I have today (7 January) confirmed with the Penn club that they still have plenty of accommodation, concession rates for people attending the conference are £81 for standard room and I think £75 for budget room.
The Penn Club are offering a special discount to Friends attending the conference. Book before January 31st to avail of the discount. To book call The Penn Club on 020 7636 4718 or email: firstname.lastname@example.org and quote non-theist conference. Space is limited and subject to availability. https://pennclub.co.uk/
For other options, see the previous post and comments. Now really is the time to book!