Not sure if you've seen, but British Cycling clarified their advice after speaking with DCMS. They've replaced the "stay local/area of the city in which you live etc etc" part with the following:
"In his response, the Minister for Sport reiterated the importance of exercise for our physical and mental wellbeing, and stressed that riders should remain as local as possible while exercising and use their common sense to determine what is and is not a reasonable distance - reflecting the fact that each individual will have different personal circumstances.
As a result of this, our recommendation is that you should ride from your front door where possible, ride within your ability and ensure that you are self-sufficient. If you do need to travel for exercise, you should do this as close to home as possible. We all have our part to play in reducing the spread of the virus, and by riding responsibly and taking extra precautions (such as avoiding crowded areas) we’ll be helping to keep ourselves and our communities safe."
Full link here: https://www.britishcycling.org.uk/about/article/20200512-about-bc-news-British-Cycling-Updated-Coronavirus-Guidance-0