I'll try to do some route fettling on BRT this evening or in the morning. We can always decide at departure time how we get to TMNH if the planned route isn't to everyone's liking (plan A will be to head off towards Terling and hang a left to HP).
Return leg will probably go thru Stock, Galleywood, Great Baddow with just a little bit of off-roading (not too comic) round the back of the Sandon Park & Ride car park to Hammonds Road, up to Boreham for a quick blast home.