To the noobs...
The reason the airlines are interviewing people months before they meet mins is because they want to get you "locked in", ie comfortable with a job offer and emotionally committed to the company after passing their grueling ten minute phone interview.
I would not fall for that, but rather keep your options open. If you accept a "delayed-entry" offer and later decline they might blacklist you...I'd make sure you understand their policy/ramifications before you accept a job that you may not show up for. ESPECIALLY if the carrier is wholly-owned, and most especially WO DCI.
If you decide to decline a previously accepted job offer, be sure and give plenty of notice (two weeks at least I would think). Write them a letter, say something about "family circumstances" or something along those lines. DO NOT simply no show a class date.
Things are changing fast in the regional world... a few months from now you might be eligible for as fat signing bonus that wasn't available when you accepted an early offer.
There's no need to accept an early offer for job security...they'll rescind that offer or send you packing on day two of ground school if it's even slightly convenient for them to do so.