Doona for Europe?

We’re traveling to Portugal with my daughter who will be 7.5 months. We’re debating getting a Doona to use as a car seat on the plane/ubers to and from airport etc. I know it won’t be great on the European streets but we’re planning to use our baby carrier around the city the majority of the time. The idea of bringing our standalone car seat/stroller seems like a lot, so looking for advice. Thanks!