In theory one could get cited for urinating in public. In practice, this seems vanishingly unlikely if you’re in a low-traffic area off a road somewhere (as opposed to in a playground or something else bizarre).
ETA: I think you’d have to decide which is least antisocial - urinating off in the weeds off the side of the road, urinating without flushing in a public restroom (to avoid aerosols), or taking a plane flight leading to much more person-person virus exposure all around.