Ben asked for our initial impression:
Mine is that it’s a personal item… that may be based on practicality, as using a garment bag for your primary luggage is not something most people do, even for a weekend trip. It’s an accessory piece.
I got stopped once and told to consolidate. I pretended to do so and when the gate agent was distracted, just proceeded down the jetway and stored it as described above.
Assuming you’re on a ticket that includes a carry-on, can you put your personal item in the overhead instead if it’s the only bag you brought on the plane?
A great solo travel tip spotted this week on One Mile at a Time.
