If you have a hacked console (paperclip with a 1st year console, modchip with later ones), you can back up your saves using a homebrew app (checkpoint) if you remember to do it regularly.

You can also copy the saves off the console (or the emulated NAND you're supposed to create when hacking it) by running a different app (TegraExplorer) right from the bootloader. I had to do this when I messed up an update and my system wouldn't boot, but I hadn't backed up my saves in months.

I do wonder if anyone's attempted to get nintendo to respond to a subject access request in the EU to get their saves from their cloud service.