Not saying this is a credible source, but this is from Did Six Million Really Die?
This is taken from 3. Population And Emigration
Statistics relating to Jewish populations are not everywhere known in precise detail, approximations for various countries differing widely, and it is also unknown exactly how many Jews were deported and interned at any one time between the years 1939–1945. In general, however, what reliable statistics there are, especially those relating to emigration, are sufficient to show that not a fraction of six million Jews could have been exterminated. In the first place, this claim cannot remotely be upheld on examination of the European Jewish population figures. According to Chambers Encyclopaedia the total number of Jews living in pre-war Europe was 6,500,000. Quite clearly, this would mean that almost the entire number were exterminated. But the Baseler Nachrichten, a neutral Swiss publication employing available Jewish statistical data, establishes that between 1933 and 1945, 1,500,000 Jews emigrated to Britain, Sweden, Spain, Portugal, Australia, China, India, Palestine and the United States. This is confirmed by the Jewish journalist Bruno Blau, who cites the same figure in the New York Jewish paper Aufbau, August 13th, 1948. Of these emigrants, approximately 400,000 came from Germany before September 1939. This is acknowledged by the World Jewish Congress in its publication Unity in Dispersion (p. 377), which states that: “The majority of the German Jews succeeded in leaving Germany before the war broke out.” In addition to the German Jews, 220,000 of the total 280,000 Austrian Jews had emigrated by September, 1939, while from March 1939 onwards the Institute for Jewish Emigration in Prague had secured the emigration of 260,000 Jews from former Czechoslovakia. In all, only 360,000 Jews remained in Germany, Austria and Czechoslovakia after September, 1939. From Poland, an estimated 500,000 had emigrated prior to the outbreak of war. These figures mean that the number of Jewish emigrants from other European countries (France, the Netherlands, Italy, the countries of eastern Europe, etc.) was approximately 120,000. This exodus of Jews before and during hostilities, therefore, reduces the number of Jews in Europe to approximately 5,000,000. In addition to these emigrants, we must also include the number of Jews who fled to the Soviet Union after 1939, and who were later evacuated beyond reach of the German invaders. It will be shown below that the majority of these, about 1,250,000, were migrants from Poland. But apart from Poland, Reitlinger admits that 300,000 other European Jews slipped into Soviet territory between 1939 and 1941. This brings the total of Jewish emigrants to the Soviet Union to about 1,550,000. In Colliers magazine, June 9th, 1945, Freiling Foster, writing of the Jews in Russia, explained that “2,200,000 have migrated to the Soviet Union since 1939 to escape from the Nazis,” but our lower estimate is probably more accurate. Jewish migration to the Soviet Union, therefore, reduces the number of Jews within the sphere of German occupation to around 3–1/2 million, approximately 3,450,000. From these should be deducted those Jews living in neutral European countries who escaped the consequences of the war. According to the 1942 World Almanac (p. 594). the number of Jews living in Gibraltar, Britain, Portugal, Spain, Sweden, Switzerland, Ireland and Turkey was 413,128.
It doesn’t take long to read the entire book (not sure how many pages it actually is in physical form).