1

The Christmas market in Wittenberg ends on 21rst December, but in Berlin there is a market which actually lasts into January.
Service on Christmas Eve: look here
http://www.schlosskirche-wittenberg.de/index_eng.html

To find out about service in the Stadtkirche you can ask here
http://www.stadtkirchengemeinde-wittenberg.de/kontakt/pfarrer.html

Expect long queues in both churches.

How to get there: There is a direct ICE train from Berlin, but the schedule for end of December isn't out yet. Check www.bahn.de every a few days, then book your train as soon as possible to get the special fare. You can book online and print out your ticket, then show it to the conductor in the train with the SAME creditcard you used for booking. The special fare tickets are only good for the train you've booked.

US$ 80 to 100 are about 60 to 76 Euro. That's not much for a double in Berlin at Christmas time.
http://www.motel-one.com/en/ maybe, though I wouldn't call it homely.

2

There seems to be plenty of hotel beds over the christmas holidays. Ive just browsed hotel.de (but you can do any booking platform) with your dates, there are considerable discounts available. To look for a hotel I would suggest:

Firstly, look if breakfast is included. Though giving away the rooms cheaply, some hotels do a healthy 15 Euro plus per breakfast pP extra, this blowing your budget by itself. Since there are public holidays on 25/26th, the alternative of this coffee-n-buns thing will not work as easiliy as it would do on working days.

Secondly, look at the location. Berlin is big and public transport runs on a sunday timetable on 25/26th and maybe even worse on 24th from noon onwards. You might be happy to stay relatively close to the Hyatt, where as I understand your relatives will stay.

Since Berlin Hyatt is on the Potsdamer Platz estate, Hotel Delta, Pohlstrasse match those criteria, also Stuttgarter Hof on Anhalter Strasse. But take a look yourself.

In Germany the Christmas holiday is Dec 24th in the afternoon and evening. Public life will more or less dry up. There is some transport running in Berlin, railways too, reduced though. Many restaurants will be closed, museums anyway. Shops and markets are open until 2 pm.

25th and 26th are both holidays, shops are closed. Some Museums will open, others not, check their websites or inquire on the spot. Restaurants are opem, though some will require pre-booking, as there will be many families to feed.

3

Anhalt, I was considering the Michelberger, but it is about 4K away from the Hyatt. Are you familiar with this area at all? It looks as though it is on a main road (google earth street view) and I saw a bus terminal. Hopefully one on a major path? I will look at the other hotels now.
THanks.

4

One of the problems I see with your plan is finding a place to stay in Wittenberg.

Traditionally in Germany the main Christmas service is held on Dec 24th just before midnight. Since it is Christmas, you won't be able to return to Berlin on the same day. Thus you need a place to stay in Wittenberg. Wittenberg is a small town, it might be difficult to find a place that isn't a small pension. Not that a pension is a bad place to stay, but it is of course not the Hyatt.

That said, Wittenberg is nice town with some beautiful timber beam buildings. But you won't be able to see much if you come just for the service. Around the 24th it gets dark by 4 pm. That is not much time to see anything if you get up by 10 am, get to the train station by 11:30 and arrive in Wittenberg by 1 pm. Thus you might actually want to hit Wittenberg on the 23rd and stay there for two nights before you hit Berlin.

5

I dont know the Michelberger itself, the location however is good. Well connected to U-Bahn ans S-Bahn at Warschauer Strasse, trams (though their direction might not be of too much interest for you) and buses. Both into Friedrichshain and into Kreuzberg (across the Spree) you get into lively neigborhoods, on the Kreuzberg side with a substantial turkish and arab input.

It might be a good idea there to ask for a room not towards the street, as on Warschauer Strasse you will be sure to hear you are in the heart of a city. Cat traffic but also the U-Bahn, which there runs above ground on second-floor-level can be quite noisy. What you saw on Google Earth is btw a train depot of the U-Bahn.

6

Maybe you're interested in this: A schedule for music events in churches in Berlin and Brandenburg:
http://www.musikinkirchen.de/Public/FindEvents/publicFindEventsMonth/2012-12.html