Caledonian Sleeper have a special Autumn/Winter offer on to mark 200 years of the modern railway
A Club En Suite Room (which includes breakfast onboard and access to the Caledonian Sleeper station lounges) for travel between 3 November to 14 December 2025 and 5 to 19 January 2026 is- single occupancy rooms on the Highland routes (Aberdeen/Fort William/Inverness) for £200 and twin occupancy rooms for £250.
Bookings must be made by 30 September.
You also get railcard discounts of 1/3 on these offer fares- I've just looked for a random date in November and Aberdeen to London solo club twin en suite is £133.20, which is all right as a fare.