That could be accomplished thru a transfer ... or each member could reserve 1/2 of the dates using their points and then the two reservations can be seamlessly linked together by MS so you wouldn't have to change rooms. The transfer would be easiest way, but not all points may be transferred- so having each reserve part of the stay may be the best way to accomplish the same thing.
Either method will work and it can be accomplished with a call to MS.
Enjoy!