I don't think it's that, some people have sd cards with 500MB that work and some have 256GB cards. It's not the issue.
The only case in which it would be an issue is if the game you want is too large for your SD card, and LoZ:WWHD is less than 2gb, so it looks like your fine there.
I think that you should just use WUP installer GX2 along with IOSUHAX cfw to install the games on to your Wii U screen.
LoZ:TWWHD is known to have issues in loadiine anyway.
First follow this:
https://wiiu.hacks.guide/
It will walk you trough the steps of installing Haxchi
After your done installing Haxchi (Not Coldboot Haxchi)
Then get IOSUHAX and WUP Installer GX2.
You can find guides on how to get both of those two things on YouTube. (Don't follow any other guides on YouTube though, all of them are super outdated!)