This took over 2 hours. It got stuck at 82% for 30 min (all the while saying 1 min left), so I tried restarting it. Then it crashed 6 times at various points in the process. Then I restarted both phones, tried again, and it got stuck at 94% (with 1 min left). I let it go for 45 minutes (all at 1 min left), and then it finally finished a whole 2+ hours after I first started. I have never felt so gas lit by an app.