I don't know about you but I will not wear long trousers on a plane. I like to keep my garments aloft of the plane toilet floor. For many years now I have flown in cropped leggings. This year I paired them with a short dress and cardigan as UK weather suitable. Once I was at the hotel I whipped off the leggings, plopped on a sun hat and was good to go Canary Islands weather appropriate.
The leggings are five years old from Kim &Co on QVC. They may still be available as they had great reviews and I can't fault them. They are the denim look style but not denim. The dress is from White Stuff and again several years old. My cardigan is a recent purchase from Splendid. It's the waffle hooded wrap or cardigan in swan. It was recommended by an American blogger. I got mine from Amazon for about £36.
A gratuitous pic of the outfit accompanied by lava and a blue curacao on the beach.