Earlier quoted context omitted.
The Megabus will take you from London Victoria to Prague in 19hrs https://bustickets.distribusion.com/connections/results?depa...
Interesting that the Prague journey is 7 hours less than Berlin which is closer. Is this just because the number of stops is greater on the Berlin route or something else?
I had a friend who took the bus from London to Poland after each term at university. It was about 20 hours to the first stop in Poland, then another 12 or so going around Poland until it got to his city. (This was decades ago.)