They usually leave the business for a stable job, not expecting to return, only to find a few years later that their calling is still tugging at them, and their contacts have dried up. Or they leave for personal reasons like an illness, an ill spouse or child, to take care of an aging parent, relocation for any of the previous reasons, and other less common reasons.
Obviously, if it's the personal reasons, it's usually the last thing on a person's mind to be maintaining relationships, so when he/she comes back it is a lot like starting over, but not quite.
In your case, however, you want to make money, create some savings, and come back. That's really no different than people who have side jobs, it just sounds like you're committing mentally to a specific, high-pay job as opposed to a side job, where people feel half in and half out.
What this all means to you is, you work, make your money, save, AND continue to maintain your relationships, obtain mentors, and go to networking events (if you're job is local). If it's not, and your contacts ask you why you moved, tell them it is for personal reasons, and you will be back. If you stay put, and get offered a job while maintaining your relationships, you can always ask for time off or quit (unless you've signed a contract).
For more tips and articles by top entertainment industry career coach, the Greenlight Coach, visit www.theGreenlightCoachBlog.com