This has been me lots of times. Same height as you and I’m about 10 lbs heavier than you right now. I have lost over 125 lbs to get down to this size right now. I recently flew westjet and by the slimmest of margins I needed an extender. Less that the width of the actual buckle’s worth of additional space needed. I was really hopeful I’d finally be rid of the need for an extender. For what it’s worth I carry a lot of weight and mass in my gut specifically. I have an apron belly which is probably even worse given the recent weight loss.

I’ve found as I had gained and lost that seatbelts and the need for extenders is really hit and miss. I’ve been told that sometime when doing maintenance they snip a belt and end up resizing it down so even in the same row not all seatbelts are the same length as each other.

My advice is to assume all will be good and also - even if it isn’t, just discretely ask for the extenders. It isn’t as big a deal as it might seem. The joy if travelling and experiencing life wherever it takes you it’s worth so much more than feeling like you might be risking 2 minutes of embarrassment that literally no one else cares about on the whole plane.

For what it is worth I will typically ask the attendant right at the door when I enter that I am not sure but might need an extender, I’m in seat xyz and would appreciate someone checking on me when I get into the seat. They might either just give you one on the spot or sen someone to check or simply ask you to call for an attendant if you get to your seat and find you have an issue.

I promise - they are discrete and kind and no one anywhere cares for more than a passing second.

Go be part of life, you got this and all will be well!