We took our daughter on a long flight when she was 6 months old. I had initially planned to take EBM but nearer the time I changed my mind as I thought - what's more convenient than milk straight from the boob!?
No need to worry then about rules/regs, ice packs etc. I wore a baggy shirt and fed her as normal - especially take off and landing. She was fine and I'm glad I didn't express.
Hope it goes well.