Microsoft has already ended all support for this package and wants you to switch. MS Office 2011 does not work on macOS 10.13 High Sierra, officially. 'Deadline' and 'upgrade' should be mutually exclusive concepts and not procrastinatory temptations. The publish date for this update was, making this is a fairly current update. The update shown in the image below is available from Microsoft Office for Mac 2011 14.7.7 Update. Both Macs have been upgraded to High Sierra (macOS 10.13.3).
I have Microsoft Office 2011 installed on 20 iMacs.