This happened to me, too, during "Snowmageddon" a few years back--and after MS was closed to boot.
I don't remember now whether I called CRO (regular Disney booking) or the resort itself...but it was after MS was closed the night before I was to arrive (early the next morning).
Disney couldn't have been nicer. They took note of my canceled flight and released the room (I suspect there were/are people at Disney who can't get out just like you can't get in, so they can probably use(d) the room)...and promised to tell MS, although I also had to call MS myself when it opened the next day.
They did give me back my points (although in holding)--
Good luck...hope you get there, even if late. W/Snowmageddon, our whole trip wound up canceled (and each call to Disney resulted in similar super service, although it was only that first night that it happened when I couldn't call MS)--let us know, ok?