I'm thinking about vacations on snowboard and I'm looking for something not far away from Poland.
The only truly all year open ski resort is Hintertux Glacier, it is in the Ziller valley about half an hour from Mayerhofen. You can also do a cave tour inside the glacier which looks quite interesting. I was there last August skiing in shorts! check it out.
http://www.hintertuxergletscher.at/en/ about 6 years ago