I've never done it with a milk substitute so you could give it a try and see what happens. I've done a half recipe frequently, because in it's current form, it makes two pies.

I've made it with a bunch of different varieties. It tastes best with moschata and maxima varieties but I've also done it with pepos like acorn and my most recent batch was a trial with a dual purpose hulless seed, pie flesh variety which was decent.