I think most successful therapy terminates in a termination session. Each person ruminates about what they got from working together and what they "regret" or think still needs working on, etc. It's just a kind of summing up. Both my T and I were retiring and moving so we sort of discussed that; what I was going to be doing/working on next (after retiring in a few weeks, I was moving and then immediately after that, going to Europe on a long-planned trip).

When I got back from the trip and was in the new home/neighborhood/lifestyle (I'd lived in the old location 20+ years) I eventually hired an online/email therapist for a couple months to work on the radical changes that had happened in the previous six months and getting settled in to them.