If the points are current for the 2005 Use Year, you can still bank 25% of the total contract thru March 31. If you close prior to that time, I'd call MS as soon as possible to bank as many points as you can. You can also ask the current owner to bank them right now- they can bank up to 50% of the total points thru Feb. 28.
If they are points that have already been banked, you'll need to try to find a way to use them by May 31. Try the Rent/Trade Board here to see if someone needs help with a rental. There may be some good opportunity for early May reservations.