So an update for those interested as of 8 pm last night...
Farringdon - clear
Thames path/embankment- generally clear a few icy patches
battersea park - went round outside, icy paths, ran on road
clapham common - went down to the junction via queenstown road and lavender hill, icy in parts, ran on road.
balham - on train, no info
wandesworth common - on train, no info
tooting - on train, no info
mitcham - on train, no info
hackbridge - on train, no info
beddington... From east Croydon very icy once out of town center
that's all I know, feel free to fill in missing areas if you know...