BCV is popular in the summer - that pool is an attraction all by itself. I think you will have to do day by day.
My advice is to call on January 10 to reserve the first night. Ask the CM how availability looks for the rest of the days you want to stay at the BCV. The CM wiill tell you if you ned to call day by day or if you can get away with calling one more time.
FWIW, there are so many members who want to stay at the BCV that I would call day by day at 7 months no matter how availability looks. IMHO, it is better to spend a few more minutes up front than days, weeks or months of stressing out over the waitlist.
Best wishes -