We're living across the border in Budapest!
Lots of Canadians here, it's kinda strange.
But I'm on my way down to Milan tomorrow from where I'm flying off to Morocco. No big Canada Day plans for me! Can't wait to travel for another few weeks.
I'm sure there's some Canadians in Vienna though - Maybe contact the embassy there, they may have info on local Canadian groups or Canada Day plans. In Budapest they usually put on a big barbeque.
Good luck!
Matt