Leaving the organisation will not change anything you've sent.
Invitations will stay in everybody's calendar. The issue is more removing them if needed. As the owner left the company, there'll be no way cancelling them, all participant will need to remove it from their own calendar.
Not know much about Gmail but I do found some information like "Turn on Exchange resource booking for your Google domain", please check Allow Calendar users to book Exchange resources and see if it could help.
Besides, from Exchange side, if they are using O365 email accounts, Sharing Office 365 Room's availability to external users should be able ...
The top answer as of April 2021 fails to highlight the whole day, just events in that day. Thus if you have no events, nothing is highlighted.
I think the author was looking for something more like this:
Below is the steps to get the background hours for a whole day highlighted as mentioned by Kylie on slipstick and tested on Office 365.
For a quick semi-...
As of Thunderbird 78.0, there is a command-line way to open .ics files in Thunderbird. This means it will be easy to add file associations now.
Personally I think, the Auto forwarding meeting invites method should be the best workaround for your issue. While the question now is that you do not would like your meeting details been forwarded at the same time for security. What I can find is that maybe we can use VBA scripts along with the Auto forwarding rules to forward the meeting invitations you ...
Indzara.com seems to offer exactly the feature you are looking for in the premium version of their calendar template. The price seems a bit steep, but looking at the time you'll save compared to modifying and extending the free template's conditional formatting rules - it might just be worth it.