Good afternoon Cruisequeen,
The Factory is a few miles from downtown Hilo, and a mile or two off the main highway (road through the plantation). Seems like a two-way taxi ride would be more expensive than renting a car for the entire day. When I visited the "Big Island," it was for an extended stay, not a cruise, so I'm not familiar with the cruise port area or how difficult it would be to rent a car or arrange for other transportation.
I hope this helps, and have a great vacation!