For your best chance of seeing fireworks, request a room on one of the upper floors on the left side of the Lodge. I know there are threads on this forum that list specific room numbers. Try doing a search.
The Magic Kingdom is fairly far away from the Wilderness Lodge...so it isn't really much of a "view", but if you know what you are looking for you can definitely make out the peaks of the castle and the fireworks are visible at night.
Oh, and you can hear the whistle from the Magic Kingdom train.