I know rule of thumb is you need an SD card that has 2x the size of your system memory (i.e. 64gb for a black 32gb Wii U). But if my console is pretty empty (no digital downloaded games) what are the consequences / risks of using a 32gb SD card, since I'm planning to immediately transfer the backup to an HDD anyway (not keeping the backup on the SD card). Is it just a matter of 'if it runs out of memory, the backup will fail' or is there more to it than that? Can I do some kind of 'free memory' check beforehand to know for sure that there will be no problems? Thanks!