I suspect if you are trying to trade into non-DVC resorts at a time when WDW usually is slow, it will be pretty easy. If you are trying to go during busy times when WDW resorts tend to be filled, it will be difficult. You should know as soon as you make the call to MS. They will be able to tell you right away for your proposed dates.
I'm guessing you are thinking about your "Plan B".
AFAIK, as long as there is availability at the Poly, there are no restrictions on the number of rooms at the Poly that can be reserved for points. So unless the Poly is sold out for the dates you want to visit, you can reserve a room there for points. (This would also apply to any of the other non-DVC WDW resorts that members can book for points).
The earliest you can reserve a non-DVC WDW resort is 11 months from check out.