travelbug: My bet is that they won't make you move. Last New Year's we had the same situation. We were told to come up to the front desk on December 30 and they would try to work it out. Sure enough when we did, we were allowed to stay in our room. Someone else was given the preferred for one night that we had. We had to check out, then check back in on the 31st. The best part was that we got a free cleaning out of checking out much to our surprise. Don't worry. Just let them know the situation when you check in and yes we got the points back for the preferred room we had reserved for the one night.
HBC