There currently is one option to travel by night train from London (United Kingdom) to Penzance (United Kingdom), taking approximately 8 hours: Namely the Night Riviera Sleeper WB operated by Great Western Railway.
Great Western Railway (GWR) operates the Night Riviera, a sleeper train running six days a week between London Paddington and Penzance.
There are two options: airline-style seats at no extra charge, or cabins with a separate reservation. Cabin passengers enjoy a complimentary light breakfast on the train.
Sleeper cabins are available as either single or twin options. Each cabin has a sink with shelf and bin, UK power sockets, USB ports, a wardrobe, and under-bunk storage. The bottom berth transforms into a sofa during the day. Breakfast is served in your cabin.
Showers are available at Paddington, Penzance and Truro, but only for passengers who have booked cabins.
Cats, dogs and other pets can join you on board – up to two per cabin. A cleaning fee is charged per cabin. Dogs require an appropriate lead and other pets need a rigid carrier. Pets must stay on the cabin floor, not on beds, and should not be taken into corridors or lounges.