I understand before the war started in Germany it was not a big problem to leave Germany for anybody. The problem was money, plenty of money, and or foreign connections. For Germans with or without Jewish heritage the problem was acceptance by other counties. Neighboring countries controlled their borders tightly, much like it is today for anybody seeking permanent residency abroad. Then, in Germany before the war started, though life was made hard for Germans of Jewish heritage, suffering from discrimination laws, they could survive somehow. Especially if they were businessmen or craftsmen. And, tragically, there were very few opportunities to move with their families out of Germany.
For anybody who is interested how life was like inside Germany, during the Nazi campaign to take power, there is an excellent book. It is written by William Sheridan Allen, an American, who, as a student, worked on a PHD thesis about life in a small German town between the years 1922 to 1945. He studdied and described in all details how the Nazis with relentless political skill, hard work, and tireless agitation changed the whole town in a few years, and what happened to many of the town's citizens:
