I have a 2.5 yo and a newborn and we're going away on a long weekend where we will be doing a bit of sight seeing so on our feet a lot. The newborn will be 9 weeks old and I'm debating whether we need a folding double buggy (seen a second hand mountain buggy gt) or just take our super light baby zen buggy for the toddler and put the newborn in a sling. We have a bugaboo donkey but its way too heavy to bring on the plane etc and want something we can take to the gate. Grateful for people's thoughts on what has worked for them as I'm not sure if we need to buy a 3rd pram!