I previously looked for this without luck, but it seems there is a manual upgrade here: https://docs.microsoft.com/en-us/office/troubleshoot/office-...
I will check it out.
I just tried the packagefile from the link, and after installing I am still stuck with MS office 365.
At this point, libreoffice does the job, and I cant be bothered to invest more time to get MS office, 2016 edition 64 bit, or whatever would be applicable in my case, to work like before catalina.
thanks for the tips though.