In my limited experience, I have found N. bicalcarata to be one of the most enthusiastic root growers I have ever grown. If you have the above ground plant matched to the pot, with the leaf span just inside the rim, you can expect the roots to get potbound very soon, with just as many more hanging outside. Not that that will stop the plant at all! I agree with the "hot & humid", too. I've heard that before, read it in books, and seen it personally at a hugemongous hothouse. The hotter it was every time I visited, the bidder the plant was.
I just got another one. I will second this other bit of advice: DON'T let it get dry! That's how I lost the first one.