December, 1942
In OTL, the Axis were unable to evacuate their forces in Tunisia by sea and as a result, hundreds of thousands of German and Italian troops surrendered. How early would a successful evacuation of Tunisia (i.e. most Axis troops get away) have to start?
December, 1942...
If the goal is to get what was left of the German divisions (15th and 21st panzer, 90th and 164th light) after Alamein out, they better get started as soon as possible, and when the weather is still bad.
I'd expect they'd end up leaving most of the heavy equipment behind (since the Italians need something to fight it out as the rear guard in Tripolitania) but presumaby Centauro and Superga get shipped into Tunisia and can cover the German mechanized troops as they withdraw.
If the Axis don't start pulling out in the winter of 1942-43, the weather gets to the point where the Allied navies and air forces can (as they did historically) prevent them from getting out.
ROM SWAG, the Germans end up with cadre for two extra armored divisions and (maybe) two extra infantry divisions in southern Italy by the summer of 1943, but presumably they can be re-equipped and brought up to strength by consolidation with the replacements that (historically) reformed the "Tunisia" divisions in 1943.
So the numbers don't change much, but the veterans of the PAA get back to the Continent. The Italians end up with the short end of the stick, and the Allied roll into Tunisia as soon as the weather breaks - call in March, rather than May, 1943.
Interesting question of what that does to the Allied timetable in the Med, if they have an "extra" eight weeks or so of campaign time in 1943...
Best,