Just wanted to let others know that it’s extremely hard to get anywhere by train in Turkey right now. I had no problems getting the sleeper from Sofia to Istanbul the day of, and the train was half empty.
But you can’t BUY a ticket, much less get a reservation, for over a week on any of the routes I’ve checked across the country unless you’re in a wheelchair. Many of the routes say they have one seat open, but when you check it’s only for wheelchair users.
Some of the routes like Ankara to Kar are booked up for almost two weeks. So if you plan to come to Turkey, do your reservations as far our as possible.
The website to check tickets is https://ebilet.tcddtasimacilik.gov.tr/