Observations/questions:
I find it more of a hassle to travel in just carry-ons than to check luggage. With the carryon, you have to drag it through the airport from flight to flight (and if I fly from BGR, my "home" airport, it's often two connections/three planes to get anywhere), hoist it in and out of an overhead bin which may or may not be near your seat, etc. For us it's WAY easier to hand the bag to the xray machine guys at check-in and pick it up at the end of the last leg of our trip.
I saw a video of a flight attendant who showed how to pack for 10 days in a pilot's case (carry-on size)

. The trick is to roll everything, which takes up less room. Check You-tube. I discovered that I could do this, pretty closely, if all toiletries were travel sized and I put the hairdryer in my backpack (the other trick- take a backpack as your personal item, they'll let you take both a backpack and a laptop case). Some of the things in my backpack are 3oz. bottles of liquid toiletries, travel sized toothpaste, and any liquid/gel makeup in a quart-sized baggie, any other makeup, clean teeshirt (that goes with the pants I am wearing) and panties, hairbrush, tooth brush, just in case my luggage goes on vacation without me. This means there's also plenty of space for other stuff, and we are always prepared for an unexpected delay- or beneficial bump!!
We always carry sweatshirt-weight hoodies with us on the plane. Wear it on, or tie it around your waist so it doesn't take up packing space. People gave us funny looks in August, but the airplanes were freezing, and we both wore our hoodies while in-flight. Good thing, too; with the airlines cutting back so much, very often there aren't any blankets onboard anymore. If you don't need to wear the hoodie, it's usually pretty easy to find overhead bin space to stuff it into.
DD and I did 10 days in WDW in August with one checked suitcase, one carryon, and one backpack. Sounds like a lot, but we had plenty of space for room decorations, park snacks, misty fans, toiletries, medications, dressy outfit (late dinner at Cali Grill), changes of shoes (necessary for me- and I am talking
crocs, not strappy fun shoes!), and changes of clothes (although I did laundry one night because we don't own that many bras pairs of shorts- thank heavens for Febreeze!!), plus tons of space for souvenirs (not WDW, but 1st trip to WWHP!!!). The only real hassle we had was with DD's carryon, as it often had to be stashed in an overhead bin WAY in the back of the plane, making it difficult to get off the plane to make a quick connection.
On that free shipping w/$25 purchase from CVS or Walgreens- do they ship water, too??

(not to start a new thread....)
SO... what works best for us in one LARGE suitcase and judicial packing, and maybe a carry-on if the trip is too long. Now, if DH were to come along, I guess we'd have to take a checked bag and two carry-ons, but then I wouldn't be the one worrying about schlepping the carry-ons

!