I'm really sorry - I can't help it, and the devil is making me do this:
Q. "How are NGBC seats with infant in the middle?"
A.
Very lumpy!
But the three middle seats should be just fine for tending to a 1.5 YO child with parents bracketing the child in the center seat - it allows one to use the lav etc. while the other does not even have to move to tend, for example.
Starting out early I suspect you may find these seats from / to ORD. Good luck!