Please update. We currently use a padded bag. Flown 10+ times. Works well. Rolls to the size of a large/cheap sleeping bag, i.e. takes a considerable amount of space such that even though it is perfectly possible to ride an open-jaw with the bag tied on top of the rear rack, this is not ideal. We also have ultra light rinko bags but used them only once, in Japan, to take the train. Storing a touring bike in them is not trivial (we have to remove both wheels and racks, in addition to the stem and saddle).

The body bag seems spacious and protecting the frame with pipe insulation should do the trick. (now, carrying these foam tubes is no better than carrying a padded bag. But it might be reasonable to fly unprotected or to use clothes on the return leg.)

Anyhow. I'd be interested to read what you think.