Fate of Clara Oswald after she went to Gallifrey

The last time we saw Clara in Hell Bent she was setting off in another stolen TARDIS with Ashilda/Me. Clara had been rescued from death by The Doctor, but she knew that her death was a 'fixed point' and had to happen - the universe depends on fixed points in time not being changed. She intended to return to Gallifrey so that the Time Lords could reinsert her into her own timeline and effectively die.

However, they talk about returning to Gallifrey "the long way around". This strongly suggests that they are going to explore the universe and were in no hurry to return to Gallifrey. Me cannot die. Clara was in a state where she also could not die. Exploring infinity seems a good way for them to pass the time.

We have to assume that Clara eventually returned to Gallifrey and died. In Twice Upon A Time, the Testimony Foundation returned to the Doctor the memories of Clara that had been taken from him. As The Testimony collected a person's memories at the point of their death, they would only have been able to do this if Clara had died.

Due to the time-travelling nature of the show, it could be possible for Clara to return to the series from whatever time passed between her leaving with Me and her eventual death.