There currently is one option to travel by night train from Padborg (Denmark) to Stockholm (Sweden), taking between approximately 9 and 11 hours: Namely the EN 344 operated by RDC.
The Hamburg-based railway company RDC Deutschland runs the RDC Euronight between Berlin and Stockholm. The train departs Berlin in the evening and arrives in Stockholm the next morning after approximately 15 hours.
The train offers two sleeping car categories. In the 1st class sleeper, private compartments accommodate up to three people with wide, made-up beds, a private bathroom with shower and toilet, and breakfast served directly to the compartment. The 2nd class sleeper has two-person compartments with a washbasin and 230V socket in the compartment; the toilet is in the corridor. 2nd class sleeper compartments can be booked privately or shared — in mixed or women-only configuration.
The couchette car has compartments for up to six people, bookable as a private compartment or as individual berths. Each berth includes a pillow, sheet, and blanket. Seats convert into berths for the night. Washrooms and toilets are available in the car.
As the most economical choice, the seating car offers compartments for up to six people and open-plan seating. Each seat comes with a power socket and an included reservation. Toilets can be found in the vestibules at the end of the car.
Passengers in sleeping car compartments — both 1st and 2nd class — receive breakfast delivered to their compartment. Couchette and seating car passengers are not provided with breakfast.