MAPS!

[Beeg]

Wow, great suggestions! Unfortunately, I'm not familiar with Venhola. I would like the map to be as big as is feasible, in summer, with river crossing (assault) as the mission.
I was raised in this area of Bavaria and it may have been a strategic location if the Soviets decided to continue into Bavaria from Austria after WW2. My hypothetical has Patton refusing to turn over White Cossacks and recruiting German army prisoners for defense. I envision the main Soviet thrust coming from the southeast, towards Vilshofen, with allied (Czech?) units securing the area north of the Danube. The town would be defended by a mixture of US personnel, Cossacks, and German civilians/soldiers. There would be a US relief column coming from the northwest as reinforcements.
The terrain is very hilly, as you said. The part of Vilshofen to the south and east of the Vils River, which splits the town, would not have been very developed at that time. That part of town is mostly new since the war. I've attached a map showing roughly what I have in mind for the force locations but I had to reduce it and it may not be legible.
Sorry to carry on like this but I'm excited about your ideas. If you have other suggestions, please let me know. Thanks much!