as Anders was mentioning the terrace is open.
You might also want to look at
The page is unfortunately in Polish, but going to
and then spotting you can find the map with teh spoting points around the airport, the description of the spots as well as public transportation map.
You can also find a schedule at
Hopefully it will updated for the winter schedule.
In case you need some help with translation or more info feel free to e-mail me at