I'll ask my family there whom I should root for, lol.
Well, I asked one of my family members. Apart from being an immigrant in Austria himself (from a culturally quite distinct country...), he is a mentsch and he said he would certainly vote for the FPÖ/Strache if he would be living in Vienna (they live in a suburb now), so some of my doubts have been taken away, though not all of them...
Meanwhile, the percentage of FPÖ votes in this poll (29,8%) is quite close to the percentage of Viennese that will vote for the FPÖ.