Biggest factor I can think of is your recovery strategy, if downtime is OK data and simplicity is key I'd honestly take option 1 and copy the files and directories directly to the new drive (with xfs or something on it).
Dd'ing anything else a la option 2 and 3 (LUKS container/LVM LV) will increase the size of your backups, because all empty blocks will be copied exactly as they are (even more so in the encrypted version as they become almost uncompressible).
That being said, its possible to "qemu-img convert" the entire 16TB LVM LV into a Qcow2 file, so you could later clone/attach it if a disked failed with the added benefit of qcow compressing those annoying zeros (but still doesn't beat the space efficiency of just copying the files cause non-zero but empty blocks probably exist).
I'd avoid option 4 and dd'ing the LVM physical volumes, because it can get a bit annoying dealing with duplicate PV UUID's. I could only seeing this being a choice if you are handling consistency somehow and want to be able to replace SSD's without much down time.
All that being said damn I'm jelly, you have as much storage in 5 drives as I do in like 20.
Sounds good to me, let's make America pay for 11/12th of the cleanup and Canada can cover the last 1/12 as per their emission ratios