I'm definitely going to need a double, as ds1 will only be 15 months (really 14.5) by the time #2 is here! I really want a Britax double, as I currently have Britax b agile now and I LOVE it. They're just soo expensive! And they only come in side by side, which I'm worried about with doorways as well. I also plan to baby wear a lot, so if I need to, I can just bring the single and wear the baby.