Just an update, flights went well a couple of weeks ago (barring a long delay on the return).
On the outbound we were able to take the car seat on the plane as it was maybe 80% full. The delayed return we held him.
swise, we ended up purchasing the new City Mini Zip as our travel stroller along with a the car seat adapter. Very happy with it and will be using it for our next flight in a couple of weeks.
Thanks all!