Question
I want to leave Tbilisi in the late evening on December 21 and arrive in Batumi early on December 22, what options do I have?
What I've found so far
According to this question from 11 years ago there was a Marschrutka and a bus leaving from Station Square Metro for Batumi at midnight. Is this still the case? What are some good evening travel options?
This answer to the old question mentions an overnight train. However, the latest train I could find at tre.ge departs at 17:05. Where can I find this overnight train?

