Yes, the IOC has such plan (yeah, I know it's not a country)
The postponed Tokyo Olympics will be held from July 23 to August 8 in 2021, the International Olympic Committee (IOC) has confirmed.
Of course, for a sports org is much easier to say "see you next year", relative to what country can do.
The US scrapped more immediate plans to "reopen by Easter", which shows the difficulty in coming up with concrete short[er]-term schedules.
President Donald Trump has said federal coronavirus guidelines such as social distancing will be extended across the US until at least 30 April.
He had previously suggested that they could be relaxed as early as Easter, which falls in mid-April.
"The highest point of the death rate is likely to hit in two weeks," Mr Trump said.
I'm not sure what the CDC officials think on this as they sometimes disagree with Trump (on more than one thing).
The more general plan you hear from other Western countries is that it will take months, e.g. for the UK:
The UK could remain under coronavirus emergency measures for as long as six months, a top health official has said, even as one expert said there were early signs that the outbreak was slowing in Britain.
Curbs on normal life may need to continue through the summer and into the autumn in order to avoid progress being "wasted," England's Deputy Chief Medical Officer Jenny Harries said on Sunday.
Harries suggested that while lockdown rules imposed last week could be relaxed once the curve of cases begins to flatten, strict social distancing guidelines will likely remain in place.
Let me add that if any government had a clear and convincing schedule for coming out of lockdowns, economists would be able to use it in their predictions. But that doesn't seem to be the case. Most such predictions e.g. from the IMF or the CBO are couched with lotsa high uncertainty warnings, e.g.:
The outlook for global growth is negative and the IMF expects “a recession at least as bad as during the global financial crisis, or worse,” Georgieva said. [...]
Georgieva on Monday said that a recovery is expected in 2021, but to reach it, countries would need to prioritize containment and strengthen health systems.
Or for the US
Gross domestic product is expected to decline by more than 7 percent during the second quarter. If that happened, the decline in the annualized growth rate reported by the Bureau of Economic Analysis would be about four times larger and would exceed 28 percent. Those declines could be much larger, however. [...]
CBO’s economic projections, especially for later periods, are highly uncertain at this time.