I bring a good carrying and a packable down jacket. Take it off before security and shove into carryon. Sneakers and warm socks and layers and a thin fleece on top. I can chafe the socks out at my destination and remove everything but the tshirt on top.

A Pact set with sneakers.

This is just not that hard - yes you will be uncomfortably cold or hot for like 15 min. Deal.
Enjoy your vacation.

I wore light jeans, tennis shoes, short sleeve, sweatshirt and my light jacket.

We do this often. We just wear sneakers and fleeces/sweatshirts. Leave our coats in the car (if we park) or at home if we get a ride. Yea it’s a few minutes of unpleasantness on either end but better than schlepping extra stuff for a week.

Nice wool cardigan, scarf, jogging pants. If it is truly freezing and I know that i will be outside for a bit, I pack a hat.

I don't pack a jacket (or I will leave it in the car)

Black tank spaghetti strap catsuit with cashmere sleeveless turtleneck and cashmere shawl. Money bag under catsuit on waist. Strip down to catsuit once off plane.
I’ve gone from snow single digits to 90 degrees in hours in this outfit many times.

We do this often. I wear thin breathable athletic/running shorts (vuori or rhone) under joggers or wide leg stretchy pants. On top i wear a light athletic tank under a light vuori zip up. A light packable down jacket goes over it all. On the plane I take off jacket and pants. Sneakers for shoes work in both warm and cold climates and are usually needed at destination as well.

I'll layer a sweater and/or a roomy jacket over a short-sleeved t-shirt, usually with wide leg knit pants and sneakers.

You really won't be in such extreme heat that you can't manage a few moments here in there in pants and closed toe shoes.

Sweatshirt over a T-shirt, leggings, socks, and sneakers. Tie the sweatshirt around your waist when you land.

I do this yearly. I wear socks and sneakers, capri leggings or capri joggers (light like Vuori), a tee shirt, and a sweatshirt. I dress my kids the same but in athletic shorts instead of capris. The walk from the car to the heated inside part of Dulles sucks but only takes 5 minutes. Then when we land, we take off our sweatshirts and tie around waist. Not difficult, and you typically want sneakers and a sweatshirt on the islands anyways for windy nights or for hiking

I do these trips often and the above poster is correct. I wear stylish black pants, fashions sneakers, tank top and a cardigan. I wear my puffy black packable coat. I take off the coat and put it my carry on once on the plane. I open the cardigan when I land. Or you could wear a short sleeve tee under a sweater.

I just did this! I layered. We never check bags. I brought an empty Trader Joe's bag to use as a beach bag+ folded it up to bring in my carry on.. I do not bring a coat...too bulky. I bring thin gloves + a ski hat that don't take too much space.

If you have TSA pre-check, you can wear boots though security w/o taking them off. Bring sandals or flip flops for the beach.

Presume you’re going to get stuck somewhere without your luggage for a little bit. Carry a coat, wear layers like a comfortable lounge set where you can take the top part off when your get off the plane and shove it in your bag, and wear comfortable slip on shoes with socks for TSA. You’re not going to be in 100 degree weather, and the plane will also be a middling temperature. And definitely have the coat on you for the trip back so if your have to take a detour or they misplace your luggage, you’re not freezing when you return.

What do you wear? Do you layer? Bring a winter coat/jacket? What weight clothes work best so you don't freeze at the beginning/end of trip, but don't get off the plane and get walloped by the heat and humidity. What about shoes?