Okay. That makes a lot more sense. I was under the impression that your AP was purchased in May.
Given that info., here are my thoughts:
The 7-day PH w/water parks from your May package does not expire until 2020 BUT it's only worth the pre-2/12/17 gate price when used for an upgrade of any sort. However, it can be transferred to another member of your party for the purpose of being used on your next trip since it has not been used.
For the rest of the family, buy whatever gets you the best deal but take the time you will spend on doing any in-person upgrades into account. If your savings is only a few dollars over getting exactly what you need, it might be worth spending the extra money now instead of spending valuable vacation time in line at guest services with your family.
Consider purchasing Disney GCs at a discount to pay the cost difference for any upgrades so that you save a little bit of money.
Upgrading one ticket to an AP could be worth the added cost but keep in mind that benefits like dining and merchandise discounts and free MM can disappear at any time, so make sure that you completely understand what you're buying before your do the upgrade. The price difference between a 7-day hopper c/water parks and an Platinum Plus AP is nearly $400 (unless you're a DVC owner or FL resident)! That's a lot of merchandise and dining. You might be better off just buying the MM outright.