What's the size of the largest patch on Wii U so far?
Solution 1:
As a response to the titled question, the largest single firmware update on Wii U was the 4.0.0 update which was 701MB.
Regarding the actual file size of Virtual Console games, currently the largest SNES game on the market appears to be Earthbound at a download size of 43MB. Assuming that all the titles you download are at 40MB, you'd be around 400MB of storage for all your titles.
- The 8GB Basic Set has approximately 3GB available for data storage and download.
- A certain amount (~5GB) of space is used by the operating system, pre-installed software, save data, account-related data and other kinds of data.
- Nintendo Land cannot be downloaded onto the 8 GB Basic Set system but you can purchase the game at retail and there is room for save data.
- If you don't have enough storage space, a message will be displayed on screen with the relevant information. You can also go to Data Management in the System Settings to see details about your available storage space.
Sources:
List of Virtual Console Games
Solution 2:
The first update was around 5GB, according to multiple tweets and sites. See here for an article, and links to those tweets.
The 4.0.0 update was indeed around 600/700 MB, as said above.
2.1 was around 600 MB source
3.0.0 downloading could take up to an hour, according to Nintendo, according to this site. Assuming Nintendo assumes not everyone has a > 1 MB/s speed, it is well under the 5GB of the day-one patch.
4.0.2 was "rather small", according to this site.
Update 5.0.0 was also small, very small compared to other in my opinion: it was ~530 MB according to this Reddit post. I bought my secondhand WiiU while it was downloading this update, it was done in under 15 minutes. I don't know the download speed where I bought it, but that's rather fast.
I didn't search for more file sizes, but I think we can take a conclusion here. I found the x.0.0 updates, which should be the largest. The first update, the day-one patch, was by far the largest - 5 GB. After that, each update was between 500-700 MB, with the largest one the 4.0.0 update (from the updates I found and listed above), which is 701 MB. I think that in the future they will most likely be around this size again.