For those who might be interested, it’s been 1 month now since I started my experiment.
I can say in all honesty that I’ve done ‘something’ in German every day since then. Some days it was small — like listening to a podcast. Other days I’ve worked on an online course from Deutsche Welle.
Have I noticed a difference? Yes, without a doubt.
But I think that more would be needed if I wanted to become truly fluent. 10 or 20 minutes a day is better than nothing, but probably not enough.
(note: this is a rough translation of what I wrote here)