My guess from the following story is they'll try to keep a corner of the country open; they won't want to postpone it from the Polish people's point of view. Perhaps they'll do it via train - I'm sure they'd get the cooperation from neighbouring countries.
Denmark, Norway, Finland, Poland and Belgium also closed their air space. France shut down 24 airports, including the main hub of Charles de Gaulle in Paris.
German authorities halted flights to 11 of the nation's 16 international airports, including Frankfurt and Duesseldorf. Germany's air traffic controllers DFS said the airspace over much of northern and western Germany was closed Friday, and flight patterns have been so severely disrupted it was hard to say when things might get back to normal.
Traffic to airports in Berlin, Hamburg and Cologne was also stopped.
Sweden was reportedly beginning to allow some flights again Friday morning after grounding all planes Thursday afternoon.
...
It was unclear whether the ash cloud would affect the arrival of President Barack Obama and other world leaders planning to attend the state funeral Sunday of Polish President Lech Kaczynski, who died in a plane crash. Polish authorities banned flights over part of northwestern Poland late Thursday, the country's PAP news agency reported. The funeral is to be held in Krakow, in southeastern Poland.
http://cbs11tv.com/national/iceland.volcano.eruption.2.1636648.html