KLM carry-on baggage

You have to read and follow the rules of what KLM (or whatever airline you fly with) says the allowance is and move on;
there is no if, and, or but about it.

At the gate, there could be a template in which the gate agent makes all pax put his/her carry-on into it to make sure the bag adheres to restrictions. The bag could also be weighed.

If your bag doesn’t meet their restrictions, they could check your bag and charge you a steep fine. Some airlines make you go back to the ticket window to check the bag forcing you to go through security again and miss the flight.

There also may be no template whatsoever.

If it is soft, don’t overpack the bag so it can squeeze into the template.

Yes, you can put your purse into one of the bags to consolidate. I do that all the time.

If you choose to buy a new bag online, I would buy it from a company that does NOT charge you for shipping both in terms of receiving the bag or having to send it back if there is an issue. There is a lot of competition. It is an unnecessary expense to pay shipping both to receive a bag or to send it back if there is an issue.

As long as your soft-sided luggage is not filled up, and so remains squishable into the requisite size, then you should be fine. Especially, does it squish in the longest dimension, from 23" down to 21.5?

I would probably see if you can pack it with everything you need and cinch it down to the requisite size with luggage straps. If it's 13-14 years old you may be about ready for a new one!

If you decide on a new one and if you have a TJ Maxx near you start dropping by there to see what they've got. I picked up a 22" 2 wheeled Travel Pro last summer at a good price. MOST of their luggage is 4 wheels but if you check consistently you may find something else. I've had the RS 21 inch 2-wheeler for several years but it was looking a bit worn and scuffed since I check it.

You can book your KLM flight on Delta if that is an advantage to you.

Don't be surprised if you're bag has to fit in a box that's sized for carry ons.

If it fits, you're good. If not, they'll give you an intentionally expensive gate check option.

I think it's better strategy to buy something you know will fit, soft-sided, and not over stuff the bag when you pack.

Bags are pretty cheap. I use only the smaller size and keep it under 12 lbs. now. I keep getting lighter the more I travel. This for example for the smaller bag (mine is Citi bags but essentially identical): https://www.amazon.com/Everest-Carry-Briefcase-Black-Size/dp/B005GUPWUC/ref=sr_1_2?dchild=1&keywords=16x12x6+carry+on&qid=1580235198&sr=8-2

Jazz+Travels: But I'm a rebel, MAN. I live by my own rulezzzzz.

But seriously, thanks for all who responded. It sounds like the consensus is I might get lucky and get my bag onboard, or I might be stuck checking it. Honestly, I'm tempted to drive up to our airport (less than half an hour away) and stick it in the Delta carry-on bin at the counter. Again, I've never had anyone question the bag, and it's always fit in an overhead bin - but also don't want to risk having to pay extra fees for an extra inch. As Pam noted, maybe it's time to pack it in (haha) and get a new bag.

Thanks, all!

One thing that I have found, is that if you are wearing a back pack, gate agents are fairly blind to it. I still make sure it meets the weight restrictions, and bring a couple of bungee cords to cinch it down to the proper size if need be. But generally they don't even ask about it. If you are holding a bag in your hand, they will definitely weigh it and possibly size it.

A squishable pack that is not packed full that meets required dimensions is not only able to be pushed into the sizing box/frame, but more likely to fit the overhead compartment than a rigid wheelie bag. Gate agents mostly eyeball the carry-ons and are more likely to cull the herd if the flight is full.

Where are you flying out of? I fly out of Atlanta and they are not strict about the size requirements. I've never seen anyone have to put a bag into a size measure device.

We regularly fly Delta or a Skymiles partner like Virgin Australia, Korean Air, Air France or KLM.
We have traveled overseas 2-3 times a year since 2010. We never had a problem with checking two bags, then my wife carrying a carryon and purse. I always carry a soft briefcase with travel docs, a couple of paperbacks to read on the flights. Also, we carry a foldable carryon to bring home books that we purchase about places we have visited, etc.

We had no issues until we took a transatlantic cruise to the UK, then another cruise of the British Isles, before flying home one-way from Heathrow to JAX, Fla. Problem was, we were on Air France and we had change of flights at CDG Paris. The flight to Paris was within Europe and stricter rules applied than when departing on an international flight from the USA. We had a weight limit for our carryons. I think it was 8-10 Kilos per person. I had to check one of our carryons for 60 GBP. Had we been on an direct international flight to the USA, I was told that we would have been OK.