2.5 year age gap: double stroller or not?

[stopgap]

By the time DC2 is born, DS will be 2 years 5 months. We live in New York City, so our pushchair comes with us everywhere, and we alternate between my son walking (sometimes for five minutes, sometimes an hour, it just depends on his mood) and going in the stroller.

My son likes to walk, but I'm not sure, even at 2.5, he could cope with walking the three or four miles we do daily, especially as DC2 is due at the end of January, when the weather here can be horrendous.

So do I buy a double, and if so, which one? Or do I stick with a single stroller and revive my Beco carrier for the newbie, invest in one of these for Jan-Apr www.allmodern.com/7-AM-Enfant-Pookie-Poncho-Convertible-Blanket-PP200-ENF1002.html, and transfer the newbie to the stroller at six months, at which point DS will be three?

can you get a second hand one?

I have a side-by-side one, but you might prefer the type where newborn is underneath the older child.

even if you only use it for 3 or 6 months I think you'll find it useful.

mine would typically useca pushchair well beyond their 3rd birthday, occasionally even over 4!

and congrats on baby!