This has been a very real topic of conversation amongst my fellow club members. We have all reached the conclusion, independently and through engaging in discussion on the club FB page, that +/- 2 hours, 25-35 miles is a reasonable amount of daily exercise.
Most of us would expect a ride to be 60-80 miles at this time of year and be out for 4-5 hours.
The general consensus is we are extremely fortunate that our sport is probably the only one in the UK which has not been closed down. We feel it would be taking the p*** and immoral to do anymore than this when millions of others can't do anything they love and enjoy.
This is simply a conclusion a large group of responsible, civilised individuals have reached through discussion. Nothing more, nothing less. No moralising. Everyone can do what they wish, simply though we all believe this is fair and reasonable.
Since the lockdown I've seen one 50+ ride on Strava and 100+ from people I know.
The club has officially set up four Zwift rides to help everyone keep in touch and having fun. These have gone down an absolute storm.