It's not a crazy concept but the solution(s) may make you crazy!
In a nutshell, I experimented a bit with Outlook calendars and tasks and decided to stay away from that.
So, ONE extension that works is Exchange Calendar (4.0.0, currently at beta5), which is available here:
https://github.com/ExchangeCalendar/exc ... r/releasesThat extension is a fork of a fork and works... mostly... with Thunderbird 52 and an online Outlook address. They say it also works for MS Exchange servers. As far as I was concerned, I was able to get the Outlook calendar in Thunderbird... most of the time but not always, and some events didn't transfer from the web page to Thunderbird or vice-versa (I don't remember). I haven't checked if, for example, adding always events in Thunderbird would work, nor I didn't check on a 3rd party system like my telephone to see if the calendars worked well, nor did I allow another person to use my calendar (either read only or read-write) to see how that would work.
Considering how hard to find are such extensions for Outlook, I wonder if it will be updated when the next major version of Thunderbird becomes available.
Another extension that I haven't tried is
TBsync. It seems to work for Outlook accounts (i.e. online) but not Exchange (corporate) accounts.
Again, I suggest you debug extensively before adopting either solution.