I had this problem 2 years ago with a two month old iPhone that was low on storage. I was devastated to lose precious photos of my twins while in the nicu. I still have the phone and periodically try to turn it back on hoping to someday recover the photos. I sent to a world renowned iPhone tech and was told basically it would take modern computers 30 years to bypass the encryption but to hold onto phone and maybe someday in the future it would be possible.