Don't let the calendar determine how good you can be. If you can truly stay in base phase for 6 months, do it. If you can stay in base phase for 10 months, do it. Stay there as long as you can. But base phase doesn't mean "run slow only". You should run by feel, for very long distances. You should also do fundamental strength building exercises, light plyo-ish work outs, and good strides/200s to keep in touch with your speed muscles/system. Not "200 workouts" or anything, just get the legs moving fast every few days. Nothing taxing to the anaerobic system though.
By doing the above for more than your standard "2-3 months base phase", you'll begin to notice results from maintaining the huge weekly/daily volume. Your body will begin to use oxygen more efficiently and you'll be running noticeably faster while exerting the same effort (without introducing any formal workouts). You'll truly be raising your potential ability by building up the fundamental strengths needed to be a better distance runner. You'll end up touching the threshold range on some runs so you don't go insane, but you'll get to the true threshold workouts in the next phase, so don't go overboard.
Then hit that threshold phase for 3 or 4 months. On top of your incredible strength you've now built up, you'll be able to handle long threshold workouts, which will be faster than ever before because of the fundamental advancements you made in your long base phase.
Then, you finally introduce real speed workouts for the last couple months. This really just brings out the racing potential in your new, fundamentally-improved body.
(.....Or, forget all this and just do the standard 6-8 week base phase, then do tempos for 6 weeks, then hammer 400s and 800s while racing each week. Be prepared for similar results to the previous year, maybe shaving off a little time here or there, before the 6-8 weeks of "hard speed work on too-little base" takes its toll and your performances begin to fade. Then repeat over and over until you retire.)