I've been asked if butternut squash will keep all winter. I'm not sure just how long it keeps, but I know I had a couple laying on my kitchen counter for six to eight weeks one winter, with no problems. I also remember having one or two of them go soft and rot, so we shall see how well mine last.
The way I most often prepare winter squash is very simple: I cut it in half lengthwise, remove the seeds, put the halves in a dish with the cut side down, and cook in the microwave or oven until about half done. Then I turn the halves over, put a little brown sugar and butter in the hollow where the seeds were, cover, and finish cooking. Now, some of my butternut squashes are too big to fit in my microwave, and I'll likely end up putting them in the regular oven, cooking one half at a time, because the two of us couldn't polish off a big one by ourselves.
Somewhere I have a weight-watcher recipe where you do the same things I just mentioned, except you mix some chopped apple, a little chopped celery, and a tablespoon full of walnuts with brown sugar and add some cinnamon. Cliff especially likes squash prepared this way.
I see no reason why a person couldn't make squash pie, substituting squash for the pumpkin in a pumpkin pie recipe. In fact, I found a recipe HERE.
Winter squash is high in vitamin A; one cup contains about three times the vitamin A you need in your diet in one day. It's super low-calorie, so even with a small amount of brown sugar and butter you might add, it won't ruin anybody's diet. Nutritional value found HERE.