Normally, we pack (2) rolling carry-ons for the 4 of us. In those, we pack our dry foods, dishware, umbrellas, ponchos, medicines, extra shoes, and anything else we won't need access to during the flight. Then, we each have the MotherLodes so those get packed with everything else for the trip. That means ALL of our clothes and toiletries, plus everything we would use on the plane like headphones, laptops, iPad, phone, and even our travel pillows. For this trip, we will EACH have a rolling carry-on (3 total) which means all of our clothes, shoes and toiletries can get packed into those. I am ordering paper plates/bowls and I'm also not going to just add the dry foods to our grocery order instead of packing them so we won't have those to worry about. That means that the backpacks will be relatively empty. We will only need to put the stuff we will need on the plane, plus maybe a small packing cube or jacket, but they definitely will not be stuffed. The more I look at them (sitting here empty), the more I think that they don't look any larger than my "boarding bag" which is what I dug out as an alternative. They are very thin when they are empty and I know we won't have enough stuff to stuff them full.