I used a sling with my DD last month, it was convenient to have my hands free and meant she could sleep on me for most of the flight. I did have to completely unwrap it at security, but they held the baby while I tied it back on. I am sure you can take a light buggy right up to the gate too, but I didn't this time. When she was awake I had a couple of baby toys for her to hold, chew etc.
The passenger next to me was not up for holding baby, earphones and no eye contact at all, poor guy was definitely avoiding! On a long flight like yours there may be nearby passengers who will hold baby for a while?
Are you weaning at all? Maybe take some fruit slices to taste as an 'activity'. How about making up a clear plastic bottle half full with dried pasta or rice and glitter or shapes and beads, when you turn it slowly different things are exposed to catch baby's attention. (Top tightly on or glued!) Little buggy board books to chew read.
Calpol sachets just in case. Extra dummy or soother if you use them.
I'm sure you'll be just fine. They are at their most portable at this age even though it seems like a mammoth task.
Are you going somewhere nice?