I haven't been to those cities but hear they are family friendly, so yes, bring your stollers. I would not advise a double, side-by-side stroller though since some areas, such as Tallinn, are very old and some of the streets are narrow, making navigating a dbl stroller a bit difficult. It might be easier to take two umbrella type strollers which are also easier to store in your cabin on the ship.
I'd love to hear how your little ones liked it.
Luisa Frey Gaynor
Family Cruise Editor