Keep in mind that the K visa expires 6-month after the medical exam, not the interview.
Also, contrary to what many people say here, it can certainly be a good idea to for your K1 to come first. Its common in the Philippines for the aunt and other relatives to care for the child, and there are many many reports on the Philippines forums/discussion groups of problems when the K2 comes with them right away. Many of these K1 regret not coming alone and getting settled in their new home assuring everything is stable with their family life before bring their K2. The 1 year "K2 to follow" option may be the best balance. Only you know your unique family situation and culture and what would be best for you and your fiancée.
But to the other people's point, I would agree regarding the school district issue, you can do all that well ahead of time and to go beyond that, to get deeper insight, will take for years and probably not until the child is already attending school, .. its not a valid concern ... but establish a home, family life, and so forth are great points, many of which people greatly underestimate ... depending on many many variables that no one here has any idea what yours are.