Usually when we go to Florida, we end up flying with Delta, so we've developed our system to deal with the lack of pre-boarding priveleges. What we do is one of us takes the carseat, stroller and at least one carry-on bag (usually a backpack) and get in line when the zone prior to ours is called, while the other waits with ds and lets him run around for a few extra minutes. I'm the car seat installation "expert" so usually it's me boarding first.
I break down the stroller on the jetway and board the plane with bag and car seat. This is where a backpack comes in handy because you can wear it which keeps your hands free to carry the seat.
Carry the car seat like an upside down "L" over one arm. This allows it to pass more freely down the aisle withOUT you having to hold the thing over your head.
When installing it, I always recline the airplane seat and pull the seatbelt almost all the way out. Buckle the seat in like I would in the car (r/fing or f/fing), then put the airplane seat upright which usually snugs it right up. Another thing you can do when the seat is f/fing is twist the latchplate around once so it's "backwards" which makes it easier to unbuckle at the end of the trip.
By the time I'm done, dh and ds are usually boarding the plane and no one is blocking the aisle while the seat is being installed.
Once you've got a system down, having a car seat at the airport isn't that big of a deal really.
Hth.