Just a follow-up with what I use now.
As a replacement, I ended up setting up Nextcloud AIO container set and so far the experience has been pretty good. I do occasionally have to go and do the update manually but the AIO interface makes it pretty straightforward.
The limitation is that I don’t have a very strong machine to host it. I have cheap VPS with only few gigs of RAM so I could give 2G to the nextcloud machine, which prevents me from enabling the more resource-hungry features, on the other hand the base NextCloud with caldav/carddav (which really is all I need) works fine.
I think we have one free chair left after UK, so…