Hi, I have an iPhone 5S running iOS 7.1 and I am planning to transfer to an iPhone 6S Plus tomorrow that is running iOS 11.3. I was just wondering if I backup the 5S on my computer, will the iOS 7.1 backup be compatible with iOS 11? Thanks so much! P.S. I cannot update to any newer version of iOS on my 5S due to it being locked to a different carrier not available in my country. Thanks again!