Sooo... Question about Children's python caging.

My lil' buddy Sam is currently 31" and actually fairly personable, compared to the more shy demeanor I've read they have. Currently have him in a 20g long, and I understand most species don't actually like large spaces. I was wondering if that is correct for A. childreni? Everything I've read describes a typical ball python enclosure, and my friend has one that I guess is what he calls active. That thing has nothing on Sam, though. He scoots around his cage all the time, day, night, whenever. I also have noticed he doesn't really ball up like I've heard they typically do, he more just lays in a pile under his log and rests his head so he can see what's going on. Think maybe I should upgrade the tank to one with a bigger footprint? Or should I keep him in his current one?