My phone updated Christmas Day and crashed itself into a dreaded boot loop. I tried everything over the last week to no avail. On the rare occasion I could even unlock it, it would freeze and go back into the loop all over again. Finally, someone gave me the advice to let it die (again) and leave it be for awhile. When it finally allows you to unlock DO NOT open anything. This will cause the freezing and rebooting again. From there, plug it into iTunes and do a backup. It took all night, but it worked! Phone was still on this morning. I tried to do a restore from the backup but opening the settings to turn off Find My a Phone caused the boot looping again. I didn’t want to wait for it to die and repeat the process til it connected to iTunes, so I just threw it into restore mode.
and here is where it got stuck on Estimating Time Remaining. For. So. Long. I didn’t believe in this thread’s magic. A few pages in, it was still estimating. By about page 3, it changed to a real time! 4 hours. Then 6 Hours. 9 hours. 10 hours. 11 hours. 12 hours. Throughout the course of reading, it has jumped between 10 and 11 hours. I use my cursor to mark where the progress bar has loaded to, and there’s slow progress being made. I wish it was as quick as everyone else in the thread, but it’s something.
EDIT: 4 hours later and it’s still at 9 hours. Slowly but surely loading. I think everyone prior to me used up the magic.
EDIT 2: it actually took 9 hours, so iTunes really wasn't joking with that estimate. maybe the magic will keep working for someone else.