I'd book SSR now just for peace of mind. It doesn't cost anything and that way you know you have a place to stay no matter what.
If you call right at 7 months, you shouldn't have a problem getting BWV - you probably won't be able to get a standard view or a guaranteed Boardwalk view, but even those ae possible, especially if you are willing to use the waitlist.
It will be a little more difficult if you are going the week of July 4, but I belive even then, you will be able to get a PV - Pool/Garden room at 7 months. My advice is to call as soon a the 7 month winodw opens, though.
Summertime is actually one of the easier times to book the BWV.
Best wishes -
P.S. Congratulations and welcome home!