Problem: Thunderbird's calendar loses the ability to update my Google Calendar. I assume this is Google messing with OAuth or Thunderbird specifically to "encourage" direct Google Calendar use.
Solution: Host my own CalDAV server.
This will probably give me two problems (or more).
@VileLasagna Hey, hey, looks like my NAS (a Synology) has a calendar with CalDAV support... since I work from home, I can probably make this work pretty well without opening up anything to the Internet at large.
It's been a steep learning curve but it's cool that most of the stuff just works (TP-Link #Kasa and #Tapo, #Ikea Zigbee, #Philips#Hue (using the Hue Bridge, not directly connected to my Zigbee coordinator). Some stuff this uses the cloud (but can be used locally), other stuff takes out the cloud entirely. (1/2)