@jmw150
That's a lot of encrypted empty space
@jmw150
This is apparently normal in either case.
Online resizing an ext4fs from 1 TB to 2 TB, on an RAID1 lvm2 took about 1h40min on a pair of seagate barracuta 2TB SATA drives. This was the root partition.
https://serverfault.com/questions/213693/how-long-should-resize2fs-take-on-a-1tb-partition