I recently took the DFDS ferry from Newcastle to Stavanger. It takes over 20 hours, and is quite expensive. Even the bars on board charge Norwegian instead of British beer prices. But it’s good fun, the accomodation is pleasant, and there is even a cheesy live band.
But the route is closing at the end of August. According to one of the crew, it’s because of Rising Fuel Prices. Another factor is that the ship has Norwegian and British crew, who are more expensive than Polish crew. There is a vague hope that another company will buy the ship and continue the service, otherwise there will be no ferry from the UK to Norway (except possibly from the north of Scotland). Car drivers could fly and rent, but Norway is a great place to explore in your motor home or on your motor bike. You’ll have to go via Denmark instead.