Minor annoyance: Updating apps when there isn't enough space on the disk screws up the previous version/existing install, too

You've probably heard about these low end Windows laptops that previously came with as low as 32GB flash storage and nowadays 64GB flash storage. Obviously space is an issue (and the old adage, that there isn't a big enough drive that you cannot fill up with crap still applies), but if Windows doesn't find enough space to update itself, it simply doesn't update itself and the existing install still works. PortableApps.com apps don't. Is it a bug or a feature? It would be cool it the installer would be aware of the free space required and/or had same sort of mechanism that makes sure even if installing the new version of an app fails, the previous version at least still works.