That is the $1 trillion question!
Actually, if it is for a much longer period, the cost of the question will go way up beyond $1 trillion.
This story is from March 16, but the guts of it remain very valid, How long will social distancing for coronavirus have to last? Depends on these factors.
We are not going to have a vaccine anytime soon. We don't know if the virus will "ebb" in the warmer summer months and then come back with a vengeance in the fall.
At this point, the things I think we do know is that we can mitigate the impact of the virus if we implement social distancing quickly and comprehensively.