Unfortunately, this means that you have no choice but to find a way to make it work if you have a limited connection. Blizzard does not yet have a release date for the update – the company issued only an early notification, probably because some users may create problems if they suddenly need to reinstall an entire game when they expect only one patch. Once the gaming giant announces a date and time, you can properly plan and schedule your other downloads for a later date.
Here is the company announcement in full:
"We wanted to get ahead of ourselves early and let you all know what to expect with our next big patch. We do not currently have a release date or time with that, but we will update this topic as soon as we do.
The next big patch will have some pretty fundamental changes in the game client. The number of back-end changes we are applying is substantial enough that we can not correct the current content efficiently. As a result, when the next patch is released, the client will be fully reinstalled to handle those changes. We understand this is not ideal for people with limited connections, so we hope this ad helps you prepare for the next update.
Thanks for your patience with this subject, and we'll see you all in the game! "