If you've been upgrading to newer Windows 10 builds via Windows Update over the last few weeks, you'll be glad to know that Microsoft has implemented a new feature which makes it super easy to upgrade a device that is low on storage. Windows Update will now prompt you that you are out of space, and will ask you to either clear disk space or use an external drive.
What this allows for is easy upgrading to newer builds without needing to clear lots of disk space. So instead of clearing out that dodgy unnamed folder you have hidden in C:\Windows\System32\SystemStuff\untitled folder\untitled folder 2\, you can simply plug in a 16GB USB stick and Windows will be smart enough to take advantage of the extra disk space and get you updated to the latest build.
This window pops up during the download/install process of a new build, so it won't stop you from working or anything. This is an awesome feature which many people will use, especially those on devices with very little storage, like small 8 inch tablets or super lightweight internet laptops.
Thanks for the tip, @zapellat