I still vote take your own. I can't imagine that the hard ones will hold your DD17mo well. I'm probably spelling it wrong - but the Maclauren - does it come in a double? That would be the way to go. Especially if they have a sit & stand version. I do think you will need one for your older DD too.
Here I go Debbie (told you I was just as bad) since you and DH will be there (right?) why not get TWO Maclaurens. One can push one, one can push the other. They will fold like a dream for the buses (or are you using buses). You can link them together with those things from one step ahead, but better DH could take the older DD to do something while you did something with DD17 mo??? I would say you could probably sell that and get at least half your money back when you are done. Another option would be to get the Maclauren and that little seat you can attach to make it like a sit and stand - maybe I saw it at One Step Ahead?

Know what I'm talking about????
Anyway, I'm beat. The kids were too much today on top of 2 hours sleep last night. Have a good one ladies.