You are right WW, some dogs do it or can do it.
My dogs can do it, well some of them for competitions all over the world but they are trained to be at ease for long periods in a crate in a noisy environment. Still then I calculate that they only perform at 80 % of their capability due to the travel, the rush of the competition with having a jet lag. I always keep that number in mind and will compete accordingly.
Your dog can do it because you trained him for it and there is a big difference between being on the Island for 10 day's or 5 to 6 months.
No, I wouldn't do it with an untrained dog for so many short periods in a year. Looking at the breed, being a GSD, I would certainly speak against it because of their weaker hips which is a disadvantage for traveling long periods in a crate, even if that crate is big enough for them to stand in. It is just a to heavy burden for them and you will not see it in a young dog but wait when they turn 10 and you have a dog who can almost not stand anymore on his behind legs for sure.
Acira