Your post above says "2 a 2 k ages 13,13,& 6." Do you mean you have four or five. If 5 and you want a studio then BCV is real tight fit. No studio is ideal for five but Poly provides and extra shower area and far more space than BCV. Moreover, with 5 for studios, you are limited to Poly, VGF, BRV, BWV and BCV
As to what is likely to be open at 7 months out, anything said may be affected by Star Wars which might cause more demand than usual for the time period, so you should seriously consider searching now for a reservation. But in the past:
Feb 1 to the Thurs before Presidents' Day has been the lowest DVC demand time of the year. Poly has always been open at 7 months out for that time. BCV is questionable but still a chance. Other studios that have been typically open at 7 months out, besides Poly, are BWV pool/garden view , BLT Lake View and Theme Park view, AKV savanna and standard view, at least at Kidani, BRV, SSR and OKW; Ones unlikely but possibly still a chance are BWV boardwalk view and VGF; highly unlikely are BWV standard view, BLT standard view, CCV and AKV Club level and value
Time between MLK weekend and Jan 31: right now the last weekend of Jan (Thurs through Sun, Jan 23-26) is an unknown. The NFL Pro Bowl may be in Orlando, where it has been for the last three years, or may move to Miami, with a decision likely before end of April. If Orlando has the Pro Bowl, then that weekend could have issues at 7 months out particularly for studios, at a number of resorts, although Poly, BWV pool/garden, BLT Lake view, and AKV Kidani, still have a decent chance of being open and SSR and OKW should be open. Mid to end of Jan, without the Pro Bowl, is otherwise a moderate DVC demand time and Poly, BWV pool/garden, AKV (at least Kidani), BLT lake view, SSR and OKW are usually open, and BRV has a chance.
As to hours, last part of Jan and first part of Feb are usually close to the same, although Feb will start to stretch hours a little more, but there are often some things closed for some refurb a couple weeks in Jan, which are then open by Feb 1.