My tandem is setup as a flat bar touring bike. I am using Hope V4 brakes, which are their downhill mountain bike brakes. I remove the complete brake system (front and rear) and put it in a leak proof container even though I have never had a brake fluid leak. Takes very little time. I do run external hoses with Velcro straps to keep them in place, and I don't care what they look like.
For a drop bar bike you might need to pack the whole brake assembly with the handlebars. I would put them in a kayaker's dry bag just to make sure that any leaks are contained.
There are also a lot of quick connect dry brake couplers in the motorcycle and auto racing world. I have used similar couplers on a "Jaws of Life" in my fire / rescue days, and they work very well, with very little fluid loss when connecting or disconnecting. That might require a bit of machine tool work to create the correct fittings for bicycle brake lines.