My grandfather served as a pioneer in the Wehrmacht from 1942 till the end, always on the eastern front. (Appearently he was "lucky" and was sick half the time)
When the german lines were overrun in 1944, he and two friends marched all the way through Poland back to Germany on their own. At times they even trailed the russian lines IIRC.
The first german town they reached, the town commander ordered them to help defend the city, but they snuck out and marched further back. Eventually they showed up at a rally point and managed to get a piece of paper saying they were on holiday from a NCO. They visited their families for 3 days and then went back to the war. He eventually lost part of his left leg at the Oder, which was again a "lucky" break for him, cause the russians sent him home right at the end of the war, instead of sending him to the camps in Siberia.
My grandmother (his wife) and my uncle (newborn back then) got out of East-Prussia with the last train, sitting on the coals.