Topic: ....Ugh, running low-ish on space.

Meh. I still wouldn't count out dual layered discs. I'm pretty sure that they wouldn't have even figured out how to get it to run yet. They said Wii wouldn't run dual layered discs, but then Smash Bros. Brawl happened.
PS3 never needed dual layered discs. Xbox One/PS4 support them, but those are ×86 machines, and I'm pretty sure that difference still matters if they were to get dual layered discs running on Wii U(PowerPC).
I'm pretty sure the HDD packs wouldn't even run that well off of disc, anyway. It still goes back to the programming.
If Nintendo allowed it, they could let you rip the whole disc onto your HDD, like Xbox One and PS4, so it's pretty difficult to ever count anything out.

As far as memory goes, ext. HDD, SD card to USB adapter, flash drive... Maybe you can take an HDD from an old computer and try casing it.

I'm facing the same problem myself, thinking of using a USB now. I have a couple lying around

PS4/XBO mandate you to install the games on their harddrives. The data packs for Xenoblade exist because Wii U does not have that feature.

I'd be more tempted to get the Digital Version since the Packs are included anyway. I'm not running low on space yet... I've still got like 300 GBs left or something out of 500.

I'm getting the digital version as well as the original Xenoblade since it gives me a discount on the new one. I have like 330 GB left out of 500 so storage will never be a concern.

@cookiex: What do you mean discount on the new one?

On EU eShop if you buy the original Xenoblade you get a €10 discount on the digital version of Xenoblade X. The deal only lasts to December 18th though.

@MegaMari0: In Europe, if you buy the Wii Xenoblade on the eshop you get a discount for Xenoblade X. Doesn't exist for NA as they don't have the Wii Xenoblade on the eshop.