Well if they're going to be in southern Germany, I'd suggest going across the Brenner Pass into the Dolomite region of Italy.
Advantages:
1) the Italians know how to make snow. The Austrian's don't. That's important in bad snow years.
2) The Dolimites are the prettiest most dramatic mountains you can ski next to.
3) Since you'll have kids along, unlike Austria, you're not likely to find naked patrons in the hot tubs.
4)I'd look at either Cortina or Val Gardena.
5) Lots of apartments to rent at both places.
6)Italy let's you'll get away from Americans. You'll find lots of Brits there, but not many Americans.
7) It's three hours by car from Munich.oser to
http://www.dolomitisuperski.com/January would be a better time to ski than February as holiday has not yet started. Since you've already skied Europe, you're already aware of lift line funnels and lift line combat. I've got to admit that I'm biased. If I could only ski one place in the world, I'd pick the Dolomites.
If you want to stay closer to Germany, you might want to think of Salbach-Hinterglem - about 30 kilometers west of Kitzbuhel.