I had the opposite experience. Premade formula was heavy and awkward to use when flying.
I premeasured the power into disposable liners, rolled them up and sealed them in a ziplock. I'm mentioning this method in case you're already using a disposable liner system. Your trip is short enough and you have the luxury of traveling with the other parent so you can actually do what works for you. I had to carry all that heavy formula myself. Never again!