Different Use Years, Banking and Borrowing Transferred Points

Hi,
We're a WDW family and just recently bought a Grand Californian(GC) contract with a different use year(UY). We figured we would be using it differently so it didn't matter if the points were the same use year. WDW is an August UY, and GC is a December UY.

Question 1:
If we transfer points from December to August, then, we don't use all of the December transferred points, can we still bank/borrow those December points?

Question 2:
If we can still bank/borrow the transferred points, would the deadline be the December UY (July 31) or the August UY (March 31) in which we transferred the points to?