Breeze to the Swedish church Christmas fair

NB: I will recce the route beforehand, but the actual event will remain a bit of a mystery until we get there. So some dynamic risk assessment may be needed on the day.
Starting at Brockwell park, we'll take our new favourite route to Belgravia and then cycle through Hyde park to Marylebone and the Swedish church which is hosting its Christmas fair. There'll be a coffee stop somewhere on the ride, possibly at the church. We'll return via Vauxhall bridge, through Kennington and Peckham back to Catford and Cator park.
Expect some busy roads and tricky junctions with possibly hostile drivers in the West end. You need to be a confident cyclist used to urban conditions and able to keep up with the group.
Timings are approximate as it depends how long we spend at the fair. It may be getting gloomy on our return so charge those lights.
Bring a sturdy lock.