Trip Dates

In order to get a jump on reservations at Gastehaus Hohe Tannen I need to firm up trip dates.  I'm tentatively planning on the following dates for the trip-

20 December -         Departure
21 December -         Arrival (AM)
21 - 27 December - Garmisch (7 nights)
28 December -         Munich (1 night)
29 December -         Depart from Munich

Naturally, I'm entirely flexible on the dates.  I am in no hurry to depart Germany, and could easily stay longer.  As a matter of fact, locking in reservations for Hohe Tannen based upon these dates would still enable flexibility for additional days (nights) in Munich.  I have selected the dates above on the assumption that most people cannot get away too long, but it would take about a half second to convince me to extend the trip on either or both ends.  I need a little feedback here!   Flight reservations and hotel accomodations in Munich are not nearly as time sensitive as reservations in Garmisch - these can wait until a couple months before the trip.