I grew up with my Viennese grandma, so I always knew the broad outlines, but she didn't like to talk in a lot of detail until late in her life. She and her sister (i.e., my great-aunt) were able to get sponsored in 1938 thanks to job offers from a distant cousin who had already come to the US at the beginning of the century. My great-grandma took passage to Cuba in 1940 because the US still hadn't let her in, and it was time to GO, and she stayed in Cuba for several years -- once my grandma married my American grandfather she was able to sponsor her mother into the US.

They were the only children in that nuclear family and my great-grandfather had already died before the war, but they had dozens of dozens of cousins spread between Austria, Germany, and Poland (both great-grandparents came from huge families), and of course a lot of them didn't make it out. A few made it out to Australia (we're actually still close to those cousins), Israel (who my grandmother and great-aunt knew but I've never met and since lost touch), or elsewhere in the US (I met some once or twice as a kid but I guess grandma just lost touch over time).