These days with the advent of massive shipping operations I wouldn't worry too much. Plus hydraulic disc brakes are used by mountain bikers all over. Get good quality stuff and you won't have issues. Plus with disc brakes you can still brake if your wheel is out of true. If you are truly worried use cable actuated brakes and bring an extra set of pads and if you know you are gone for looooooooooong periods maybe send a package to a hotel by a certain point. However I think we as tourists get a little over-worried and I don't think we need to these days.