I'd say, since your cab is almost 5 feet hight, you could certainly grow 1 big plant. The main limiting factor here is the 15inch depth. Though you can probably train it to grow 2 with a scrog and some LSTing. Why not germinate three seeds, see if you can get a female, and if it turns out all three are female, chuck one or find somewhere else to grow it.

I am by no mens an expert either.