I flew last night and saw a couple that had young twins. Both babies and parents did a great job. It reminded me of a recent purchase my wife and I made. We have flown nearly 40 segments with our 18 month daughter. Until recently we always gate checked our stroller which was consistently damaged. AC did a great job in compensating us for damage but after several claims and many days without a stroller we decided to find a carry on solution. Many manufacturers call their strollers carry on but when I measured them in store only one met the Air Canada size guides. And it fits in the sizer at the gate. It’s Silver Cross Jet stroller. It is expensive but has made travelling with our daughter (slightly) easier and more enjoyable recently. I am not affiliated in any way with the company I just wanted to share something helpful.