Seat belt extenders? Is there a way to know ahead of time that you need one?
It has been a few years since I last flew. As soon as I entered the plane and saw an air-attendant, I asked for one. as soon as she was able she brought me one. Glad I asked for one because without it was too snug for my liking. I also opt for an aisle seat if flying alone, I just don't want to climb over strangers. also you can get up and walk around if it makes you feel better. when you get ready to checkin they have kiask now that can allow you to change seat asignments. If your lucky you may be able to get an empty seat between you guys if it is a 3 seat row or a 2 seat row each. but don't book like that. book together and then see how full the plane is at checkin/boarding. but it is a gamble. if you want more room for sure, upgrade.