Updated route with a more direct route to Feering?
https://ridewithgps.com/routes/45105545
If you are going to chuck in the byway to Nunty's you should really do the full house and include the fabulous Ambridge Road byway
Now there's a thought - perhaps it should be recce'd beforehand though - Ambridge can get very gloopy. It's a seasonal byway I think, but farm vehicles do use it. I don't know Nunty's, but looks a logical route to Greenstead Green. I've had a look at rights of way and the track through Markshall is just a footpath, despite what RwGPS says. I know there were plans a while ago to make a cycleroute to Earls Colne, so my OS map may be out of date?
Yes sounds like a nice reccy for a weekend ride for tea and a sarnie at Greenstead. I generally ride it heading back from Greenstead directions so the following is in reverse.
The bit through from Nunty's Lane is hard pack but with a binder of mud, so can get a bit wet with puddles, esp if the logging vehicles have been through there. There's a right turn to the section from Little Nunty's Farm which is concrete pad from memory, at this right turn, there is a gate and concrete pad towards Markshall (I think there's a café there but never been yet), then there is a similar hard pack but with a binder of mud for a section before it spits you out on to course aggregate leading to asphalt for the run down to teh A120. Crossing needs some patients to get a safe gap and then it's an old asphalt road in to Coggeshall, it can be quite wet as the fields drain down it, so if it's cold enough to freeze, then I expect it will be an ice ring!
I would strongly recommend giving the byway at Clavering Farm a miss however, it is a quagmire in the summer let alone in winter and chewed up by 4x4 action.