I'm trying to take advantage of the Donkey Kong Knock-Out Offer by purchasing Tropical Freeze after Diddy's Kong Quest, but my Wii U doesn't have enough memory on it. I know I can delete stuff from my system for room, but I don't want to lose the data, and I'd rather not get an external hard drive just yet. Is there a way to just purchase a game and download it later? I haven't seen that option on the eshop, and my searches haven't proved fruitful. Also, I've tried just purchasing the game on Nintendo.com, but it isn't available for purchase there yet.
Edit: I ended up getting in touch with Nintendo support and learned that I could delete system data without deleting save data, so that will do for now. I know I didn't post this as a question, but mods can consider it answered and lock this thread if they'd like.