Hack4Glarus 2020.2 - 2020-12-04 - 2020-12-06? (No CfP yet)
Linux Expo Ulm 2020 (together with Linux Presentation Day 2020.2), Ulm, Germany - if it takes place at all,it will be on 2020-11-21
IT-Kongress 2020, Neu-Ulm, Germany - 2020-11-12 (No CfP yet)
X2Go: The Gathering 2020, Linuxhotel, Essen, Germany - some time in 2020-07, 2020-08, 2020-09, or the first two weeks of 2020-10 (trying to avoid these, though). Planning sub-page can be found here
OpenPOWER Summit Europe 2020, ??? - some time around September-October 2020 (No CfP yet)
LinuxDay.AT 2020 - 2020-10-10 (No CfP yet)
TUEBIX 2020, Tübingen, Germany - 2020-06-20 (No CfP yet)
Hack4Glarus 2020.1 - 2020-06-05 - 2020-06-07 (No CfP yet)
LinuxWochen Wien, Vienna, Austria - 2020-05-07 to 2020-05-09 (CfP Deadline 2020-04-14)