Here's what I did: I bought a new 512 GB SSD to replace my old 256 GB SSD, which was getting full. I put the new SSD in an NVME to USB adapter and then booted to a Fedora 38 live USB and cloned the old drive into the new drive using dd if=/dev/nvme0n1 of=/dev/sda. Then I used gparted to expand the LUKS partition to cover the rest of the disk. I did not have to unlock the encryption for this. After that, I powered off, removed the 256 GB SSD and installed the 512 GB SSD, then booted normally. I did not erase either of the SSDs.

Now when I get into Fedora 38, GNOME Disks reports that /dev/mapper/luks-5e5f911c... is a 511 GB ext4 partition with 80 GB free, and /dev/nvme0n1p3 is a 511 GB LUKSv2 partition, but when I run df, this is what I see:

nate@redgate:~$ df / -h
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/luks-5e5f911c...  233G  159G   63G  72% /

What did I do wrong?