Double stroller in Ireland?

Hi! We’re leaving for Ireland in a week with a 9-month-old baby and a child who’s almost 3 years old. We bought a double stroller for the trip, but I’m starting to have doubts.

At first, I wanted to bring a compact stroller and a baby carrier, but we’re traveling with my in-laws and although they’re in good shape, I’m not sure how comfortable they’d be carrying a 20lbs+ baby for several hours (my oldest gets tired quickly walking, and sometimes we might do activities on our own while they stay with the kids).

The stroller is really long and takes up a lot of space. I’m able to use it on Montreal public transit and it folds fairly easily, but public transit here is pretty big. What would you do?

We’ll be visiting Dublin, Galway, Cork, and Killarney. We won’t be renting a car, only using trains, buses, and local public transportation.