Hoping someone can help me on this. For Christmas last year my wife gave me one of those North Face heavy-duty vinyl duffel bags. It's technically larger than the airline carry-on size requirements but it can easily be squished to fit.

Anyone know if these types of bags are treated like standard hard sided luggage or will they look the other way because it can be squished to fit? Realistically I can fit it anywhere a normal carry-on can fit.

Thanks!