If you look at what’s going on in the UK already in terms of rules being ignored outdoors... I would say that if we make it as far as theme parks opening without a second spike... Then social distancing outdoors is unnecessary anyway... Because if it’s essential for keeping that R0 down, it will 100% be going up after this weekend...
You can see here that the UK deaths are still really high in comparison to the rest of Europe. We are on fragile territory right now and irresponsible actions will lead to a spike in cases, the NHS getting overwhelmed again and everything having to shut down. It's really unfortunate we don't know how many British citizens actually have antibodies (due to lack of government testing...), as if we did, we would know the level of immunity we would have as a society and how to act appropriately moving forwards.
We are on thin ice right now, most people think it's "over", but with the way things have been this weekend, we are just weeks away from a second wave. On the other hand, things across Europe have been really promising and despite relaxation in measures the deaths have still been continuing to fall, so who knows what the trajectory of this virus over the next couple of weeks will be.