I noticed the GoGo Baby website says the older scenera is incompatible. Do you know what year your scenera is from?
Your dd is about average for height and weight. If the scenera doesn't work, maybe try the Safety 1st Guide 65. It RFes to 40" or 40lbs and lasts most kids FFing to booster age. It's a compact lightweight seat too, and costs about $80 at Walmart.
It looks like most of the incompatible seats are boosters.
Maybe give them a call to see exactly what they say about your seat and/or the Guide 65.
If you want to use the scenera, you should be able to bungee cord it to a rolling suitcase. When I flew alone with two under 2, I brought the stroller and fit all our stuff in a roller carry on and a large diaper bag. One child in stroller with car seat bungeed to stroller. One child on my back with the car seat bungeed to roller suit case. I 'harnessed' the diaper bag in one of the car seats. I pushed the stroller with one hand and pulled the roller suitcase with another.
Good luck! It will all work out if you plan it out and give yourself time to be patient.
If you do call GoGo Kidz, let us know what they say.