But no, he's likely been sleeping in beds since he's first class in night trains, in 3-bed compartments that generally have showers as far as I know. The lights can obviously be turned off.
If you restricted yourself to sleepers, there is quite a broad network across Germany, but still not comprehensive (https://assets.static-bahn.de/dam/jcr:5e469db8-ee74-46b0-a27...)
https://leben-im-zug.de/meiner-erster-monat-mit-der-bahncard...
So I guess he really is just sleeping in the regular compartment rather than a sleeper berth.
The trains he mentions are just regular ICEs that operate for some overnight trips.
I can imagine how this can be reasonably comfortable in an older ICE1 in first class, but i wouldn’t want to sleep on ICE4 seats for extended periods of time
Lasse travels 600 miles a day throughout Germany aboard Deutsche Bahn trains. He travels first class, sleeps on night trains, has breakfast in DB lounges and takes showers in public swimming pools and leisure centres, all using his unlimited annual railcard.
‘I’ve been living on the train as a digital nomad for a year and a half now,’ Lasse told Business Insider recently.