Should we retire the uninstall information from Hotfixes?

As we go merrily along installing Critical updates to keep our systems secure, Each installation brings yet another $NtUninstallXXXXXXX directory taking a few more megabytes of storage on the system partition. I have watched my free space decline over time and want to stabilize my space usage. Does anyone have a policy on if or when to remove these uninstall directories? My first hunch is to leave them on the system for 90days and then archive and remove them if I have no issues with that particular hotfix. Any ideas?