Inga - I hope the waitlist works for you, but I don't think your chances are very good at this point. There have been people on the waitlists for that week for quite some time. Sounds like you might have a lot of people ahaead of you. If you haven't already, consider making a back up reservastion for cash somewhere.
The best chance will come 30-31 days prior to arrival. That's when people cancel if their plans aren't firm. (No one likes to have points in holding if it can be avoided). If the waitlist doesn't come through by then and you still want to be on it, be sure to call MS and tell them so. Otherwise your request will be dropped. At 7 days there are no more waitlists. You have to call to see if something became available.
It could happen - it's not impossible, but it isn't likely. Hope it works for you.
Best wishes-