I'm currently teaching English in Japan, and applying to medical school. The schools I've received interview invitations at have been very understanding in terms of the issues associated with scheduling an international trip, and, so far, I have had no trouble with putting my interviews dates into one large trip. Before deciding to go abroad, I also spoke with several current medical students who did the same program I am on, and none of them had any troubles with scheduling interviews. However, I don't think that not returning for interviews is really an option. While I do know that some offer skype interviews, it's pretty rare, so I wouldn't count on it as a rule.
If you have any questions, don't hesitate to ask!