The issue you have is check-in date and day after. VWL, BWV pool/garden view, BLT lake view, and even BCV studios and 1BRs, and also VGF 1BRs can have openings for July 4 and 5 but some of those may disappear before you can reserve because you get a flood of members seeking those dates who start reserving about November 30 and December 1 with a June 30 or July 1 arrival dates. In other words, the fact that you will not be trying to reserve until December 4 puts you at a disadvantage for July 4 and 5. Likely, some of those resorts will still be open, particularly if seeking 1BR, but you have a risk that you would otherwise not have if your arrival date were June 30 or July 1. You may even consider walking the reservation by reserving 7 nights beginning June 30 and daily dropping and adding nights until you have what you want. in any event, SSR, OKW and AKV savanna and standard view studios and 1BRs should be open even if those others are not
Poly is too new to have any reliable history for those dates although I suspect you will also have a decent chance there. Ones that are definitely unlikely are AKV value and club level, BWV standard and boardwalk view, BLT standard view, and VGF studios; also BLT theme park view which is very often open during the summer is usually gone at 7 months out for time around July 4.