12 feet sounds safe enough for me but the experts are saying that the virus could travel up to 20 feet away. I'm not so sure if anyone is going to practice extreme social distancing after being in lockdown for nearly 3 months.
But in recent research by the scientists of the University of California and Stanford University, US, it was found that six feet distance may not be enough as the virus can travel as far as 20 feet. The research has not been published yet and is under peer review.