Hi Ira, There is a cyclocross Whatsapp group where off road rides generally get arranged, along with a lot of cyclocross race chat. Send me a PM with your phone number if you want me to get you added to the group.
We are meeting tomorrow at 9 at Four Boroughs in Crystal Palace for an off road loop - route to be decided/made-up as we go. There are very few stretches of gravel road around here so expect (very muddy) bridleways and rooty woodland trails. There will probably be a ride on Sunday as well.