I have a green card for four months now for my wife's medical exams in Iran. Doctors find travel dangerous for my wife in Coyde's covid_ 19 Can I stay in Iran longer?
You will need proof that you intended to return to the US and remain a lawful resident.
If you remain outside the US for over 180 days, but less than one year, there is a "rebuttable presumption" that you my have abandoned your lawful permanent residence. You will need to demonstrate that it was always your intent to return to the U.S.
Generally, absence from the US 6 months or more raises the assumption of abandoned green card. Possibly, COVID-19 will forgive a late return to the US.