Great post, I moved to Germany in my early 40’s and whilst my Deutsch isn’t terribly good (being in Berlin doesn’t help as everyone speaks English to me most of the time and I work in English) it does get better.
I found a daily intensive class extremely beneficial for maintaining motivation and consolidating knowledge fast-necessarily as I originally lived in the east where Russian was more common than English. I think daily is better than once or twice a week for us adult learners, even for short periods.
I look forward to eavesdropping more auf Deutsch-a strange experience i had last year in Helsinki was inadvertently overhearing a job interview in a cafe between a prospective employer and employee-the latter from a Berlin startup that I’d been following for a while and hearing what things were really like was fascinating. Imagine this ability in Deutsch ;)