Having followed my nose through Google, it seems that some did escape, and via the Pyrenees route that has already been the subject of posts here:-
On 8 November 1942,
Allied forces
landed in French North Africa. When the French authorities there submitted to the Allies and broke with Vichy France,
Germany occupied southern France.Major Bertrand, anticipating this outcome, evacuated
Cadix on 9 November, two days before the German forces moved. The
Cadix staff dispersed, attempting to reach Allied territory.Rejewski and Zygalski eventually crossed into Spain, where they were arrested and imprisoned. Released after
Red Cross intercessions, they went to Britain. There they were employed by
British intelligence until the war's end, against German
SS "hand" ciphers.
Cadix's Polish military chiefs, Gwido Langer and Maksymilian Ciężki, were captured by the Germans as they tried to cross from France into Spain on the night of 10–11 March 1943. Three other Poles were captured with them, Antoni Palluth, Edward Fokczyński, and Kazimierz Gaca. Langer and Ciężki became prisoners of war. The other three men were sent as slave labor to Germany, where Palluth and Fokczyński perished. All five men protected the secret of Allied decryption of the Enigma cipher.
https://en.wikipedia.org/wiki/Cadix
It appears that the five men mentioned at the end were not only brilliant codebreakers but brave ones as well. What a waste though that they were being shuttled around Paris, Algeria, and Southern France instead of joining Rejewski and Zygalski's successful,
albeit belated, escape to Britain. They may or may not have contributed much there to the already successful efforts at Bletchley Park to prevail over Enigma, I don't know, but its secrets would have been much better safeguarded. As it is, we must celebrate the quiet courage of those five Poles and the typical efficiency of Nazi Counter-Intelligence.