Mr. Laser Beam wrote:
^ Or perhaps Charvanek managed to get ahold of them and let them go. She could have given them some old freighter with clearance codes to get them safely out of Romulan space (just like with Spock).
I think that unlikely. For starters, the Romulan state did not know about Spock's presence in Romulan space the first time, while it certainly does know about the eight other C survivors. Spock also had a patron inside Romulan society protecting him: after Tasha's execution, their fate will rest in the hands of a Volskiar who isn't depicted in Treklit as a generous kind of person, especially if he's felt himself cheated.