I always stay the night before an intercontinental flight awake to avoid jet lag. In theory space is limited but in practice this has never been a problem for me. They will tell you it takes three days but always multiply by two. I have once lost a day in Paris because a bicycle was late. German Railways also has a hotline, 0180-3194194, normal business hours only.
Prices are unreasonably high, travel times are enormous, and service is very spotty.
It's just not an option. The one exception was my Crater Lake tour, where we went from San Francisco to Klamath Falls in Oregon because only small planes that do not carry bicycles land there. To ship bicycles overseas, I used to use a fiberglass box. It has made some 40 trips now and it is cracked in many places. I have also shipped bicycles in airline-provided cardboard boxes, which seems to work surprisingly well considering the damage to the fiberglass box.