It depends. If you want July 4th timeframe, it could be very difficult. If you want other times in July, you may have a better chance to get what you need. Just remember that popular times get booked quickly by members. Members can make their reservation 11 months ahead of time at their home resort. So if you want a Grand Villa, popular time of the year, etc., try to get as much lead time as possible.
BCV tends to be sold out faster in the summer because of access to SAB. We tried for early June about two months ago and it was sold out.
If you are flexible with the resort, you have a better chance, too.