Queen Elizabeth hunting lodge (currently closed). There are usually plenty of parking spaces and it is only 10 minutes walk from Chingford station,
The risk paid off and we had a lovely 4/5 mile walk with only one or two short showers. Because of the weather forecast it was also very quiet since most people had been put off by it.
There are a mass of walks you can take from this starting point. We started along the Holly Trail then went through various woodland paths that took our fancy. The thing about Epping Forest is that it is very difficult to get seriously lost since eventually you will come across a road. A GPS app such as this one from Ordnance Survey helps (£2.99 per month).
Due to the mud and puddles thanks to all the rain we had recently it was definitely "Wellie weather" but boots and gaiters would have also worked.
Highlight of the walk was at the end with my sausage & bacon sarnie at the Butlers Retreat.