One of my old bosses hid out in the mountains of Czechoslovakia until near the end of the war. Then his family trekked to Italy somehow, and went on to the US. Along the way, the mother changed the family’s surname to protect everyone. Of his relatives, only my old boss (who was a boy), his mom, a younger brother and a younger sister made it out. The rest of the family (including his father) were caught and sent to, IIRC, Dachau.
I also worked on a documentary where I met a very old survivor, Mariam Cohen, and her son, Kurt Fuchel, who had been part of the der Kindertransport that got some kids rescued and placed in England. They didn’t see each other for almost 60 years, until he found her in a nursing home in New Jersey. He assumed that she had died. The son was teaching at Princeton, and he discovered that his mother had changed her name, immigrated to the US, remarried and had had more kids.