Twice a month, or when I got some free time

every week for solving some tasks

From time to time, to check if Erik or tbs are around to discuss about how to improve the site again

Comes in cycles .. some very active periods (once a day) followed by quiet months where I try to rebuild my confidence by attempting some other sites.

Oh no. Just signed back in because now that I can code a bit I wanted to try more of the programming challenges... and now I get to see that this site is dying.
That's sad. I think it was the first challenge site I that I ever found... about... 12 years back?

Nothing has changed, and yet everything.

is there a place where this community has migrated or keeps in touch? An IRC channel?

Once a week to once a every two weeks.