Totenkopfschwärmerraupen - was beachten

Hello rat, I don't speak german very well so I will reply in English

The deathshead hawkmoth is continuously brooded. This means they can have unlimited generations without needing to overwinter.
Your pupae will emerge this year if you keep them warm enough (room temperature).
It is possible to overwinter them though, but it is optional. By keeping them cool (around 5-10 degrees) they will go into a diapause. If not, they emerge.

In most of Europe, Acherontia atropos will not survive the winter.

This is because Acherontia atropos is native to Afrika, and some parts of South Europe (Kreta). They need a very hot climate.
The reason they are found all over Europe is because they are excellent migrants. In summer, they can migrate from Afrika all the way to Sweden and Russia.
They are however not fit to survive in these climates. Most Acherontia atropos overwintering in the northern parts of Europe will die from the cold in winter.

In Afrika, they do not overwinter at all and spawn continuous broods.

If you plan to release the moth outside then yes, I would overwinter them.
If you plan to breed them in captivity, then there is no need for overwintering.