bar with outdoor space ?
if you're fine with no bar scene and just beer & wine, you can do antique cafe on 26th @ 6th -- european cafe tables in a courtyard. or, perhaps better yet, just go to shake shake. don't have to wait in the long line for drinks only and you'll be sitting at a table in one of the prettiest parks in town.
otherwise i think you mostly have to get a bite or take your chances with a rooftop
- bread bar at tabla (patio)
- markt (sidewalk)
- hotel giraffe (rooftop)
- grammercy hotel (rooftop + reservation)