We spent a week at Marco Polo Club (which is in Hinterthal close to Alpenland) in September of 2015. There were a number of restaurants open, Urslauerhof, Landhotel Schafhuber, Almhof and Theresia are some we enjoyed.
We had a car, but as AlohaKauai said you can pick up the train at Saalfelden. Maria Alm is a pretty town to wander. Our resort had activities that you could book through the resort which might be something to look at if you won't have a car. ( Is there a reason you don't want a car?) We did do a couple of hikes through the resort.
From the resort we did the Werfen Ice Caves, which are the world largest. We drove the High Alpine Road. Hiked Krimml Falls. Drove to the Parish Church of St. Sebastian. Other sights you can see from this area, which we have done on other trips are the city of Salzburg, Hitler's Eagles Nest, Hallstatt, although we did that area when we stayed at Grundlsee.
We have traveled to Austria a number of times but this is the first time in this area and we throughly enjoyed it. I know you are booked into another timeshare, Marco Polo Club does have a partial kitchen in all units, even the studios, I think. We had a 1 bedroom with a living room and it was very nice.