anyway, the best case scenario is that you go to Urząd Miejski (or Urząd Miasta - it's the same, but they use different names sometimes) and they should register you to vote (you will probably receive a piece of paper stating that you're not "zameldowana" anywhere - and you have to bring that paper with you to the voting commitee, anbd the ID card/passport as well, of course), but that's how it works with Polish people who can't vote in the place they live. if there are different rules for your case, then I don't know
Thank you very much for this Krzysztof! I do speak Polish and I'll give the Urzad Miejski a go next week.
And no, the twins are definitely NOT an option for me...