DVC has two reservation windows. Beginning 11-months out from date of arrival, an owner of a resort can reserve that resort (and only a resort he owns) for up to 7 nights; he can add nights thereafter. At 7-months out, an owner at any resort can reserve up to 7 nights at any other resort (and add days thereafter)
The initial issue is having someone willing to rent. You are more limited at 11-months out because you, or the broker, must find an owner of the resort that you want who can rent the amount of time you want. For an 11-night reservation, you mention possibly trying for two reservations. The reality is you may have to try for two reservations because no one owner, who is found and may be willing to rent, may have enough points to reserve that many nights.
The next issue is availability. DVC at WDW has two demand seasons. The low to moderate demand season runs from the day after Marathon weekend in Jan to late Sep. The high to extremely high demand season runs from late Sep to marathon weekend in Jan. You want time in Oct, which is high demand, with about the middle 2 1/2 weeks of Oct being part of the extremely high demand time.
There are certain rooms that can be difficult to get even at 11-months out many times of year. Two of those are BWV and BLT standard view studios. During that high demand season, those can often disappear within moments after 8 a.m. eastern at exactly 11 months out, when the 11-month reservation window opens. In essence, even if you can find an owner who can rent one of those and is willing to make the attempt at exactly 11 months out, you still have a risk of failure simply due to the fact that the owner's particular computer may be nanoseconds slower in communicating with Disney's computer than some other member's computer. And if you have to get a second owner to reserve additional days, you have the same risk of failure for those. Other studios that have a risk of disappearing at exactly 11-months out for that time of year include AKV value and club level studios, CCV studios, VGF studios and BWV boardwalk view studios. Studios that typically last for some time into the 11-month window are AKV standard and savanna view, BLT lake and theme park view, BRV, Poly, BCV, OKW and SSR. SSR has the highest chance of being open for majority of dates in Oct at 7 months out, followed by OKW and AKV Kidani savanna view (but even for those some dates can disappear before 7 months out). Other studios are more likely to disappear before 7 months out.
If you plan to rent 11 nights in the same studio in October, you should likely first relinquish the idea that you can get low cost, near park rooms, such as BWV standard or BLT standard view studios. BWV pool/garden view, BLT lake (or theme park) view, and BCV are more realistic possibilities if you can find someone to rent them, as are BRV and AKV (except for value and club level).