There currently are a variety of options to travel by night train from Trzebinia (Poland) to Rzepin (Poland), taking between approximately 6 and 7 hours: Namely the EC 430 and the IC 430. These lines are operated by DB.
Deutsche Bahn (DB) exited the actual night train business in 2016. However, it operates around a dozen Intercity and Eurocity trains that run exclusively at night.
In these night trains, there are only first and second class seats. The lights stay on all the time and there is no way to recline the seats.