I flew in the 777 to LAX in March, CS, it was indeed too hot, and on the way back I actually bought some very light cotton trousers and wore just a loose cotton t-shirt. I tend not to use blankets when flying, whilst my wife always do, and on those flights she could not use them…

in contrast, I have just flown with QR, and they kept the cabin super cold, but ok using the blanket, and that really looks like a better strategy.