The first week of December is THE highest DVC demand week of the year at WDW, and the second week is the third highest (Christmas week is second). Moreover, studios have the highest demand of all size rooms during that and other times.
An owner of a resort can book up to 7 nights starting online at 8 a.m. eastern, 11 months out from date of arrival. You can add nights thereafter if you want more than a week. If you own at Poly or BRV, it is likely you will be able to get a studio for first week of Dec (or second week) as long as you book 11 months out, preferably at 8 a.m. eastern when online booking begins. BWV could have issues. BWV has standard view (which is lower cost), boardwalk view, and pool/garden view booking categories. Pool/garden rooms are the vast majority of rooms. For first two weeks of Dec, standard view and often boardwalk view studios can book full within moments after the 11 month window opens at 8 a.m. In other words, getting one of those for that time period can often depend on whether your computer communicates faster with Disney's computer than others at exactly 8 a.m. at 11 months out. Moreover, even pool/garden view studios can sometimes disappear at 11 months out for some of the days during that period, although those usually last for some time after 8 a.m.