There's a map to prove you wrong. I counted 26 from the UK to Turkey and from that bit of Spain to Ukraine (a different gauge doesn't mean you can have nighttrains). The solid lines have sleeper wagons. Which are useless anyways if you are taller than 190cm. https://back-on-track.eu/night-train-map/

Actually Spain seems to have more to offer according to this map http://www.night-trains.com/europe/

edit: Nope, Spain is pretty almost void of night trains https://en.wikipedia.org/wiki/Trenhotel