I would highly recommend you to reconsider the target of this hike. We got stuck yesterday in Osterhofen, because all the trains from Osterhofen/Bayrischzell back to Munich were cancelled "spontaneously" and there are no bus lines. Luckily we could found a taxi service back to Schliersee, nevertheless this might be problematic on the 25th of December...
spontenously? The railways have been warning passengers about Zoltan for a week.
Please read the additional information given on the Db.de site before taking decisions.