It makes sense to not treat all areas of the country the same.
Big urban centres like London and Birmingham will obviously have very different infection rates from rural areas like cornwall.
We need to drill down into the data and find out which parts of the UK have infection rates that are low enough to properly put in place case finding, testing and isolation, contact tracing and quarantine. Where that is possible we could start carefully lifting the lockdown. Where it's not yet possible we need to keep emergency containment measures in place.
We shouldn't be treating the whole of Cornwall, or anywhere else, as all the same either. The situation will be very different in major Cornish towns from how it is in the countryside. We need to be working with the most reliable, most local data we can get, all the way down to small rural parishes.
And of course we would need road blocks to enforce these measures. I don't understand why some people think this is so extreme compared with what we are currently all subjected to, regardless of local threat of infection.
I say this as someone who lives in London and made the decision at the beginning of March not to travel outside the capital again until we got to grips with this.
We haven't yet got to grips with this, we've just been 'having a lockdown'.
Lockdown measures immediately and dramatically slow the spread of the virus but that's all they do and only as long as they are in place. Lockdown measures just buy us a bit of time and unless we use that time wisely, to set up all the things we actually need to do, then we are still fucked.