It's worth mentioning that a lot of meat processing companies actually do a lot of butchery work on frozen meat. They use power tools to cut through the meat when it is frozen solid.
What we can learn from this is that IF you have some method of cutting the meat into the portion sizes you need, you can do it whilst frozen and return the unwanted portion to the freezer unaffected. This means that you don't necessarily have to divide it into pieces of chicken so long as you are prepared to dice the chicken once defrosted to make into pie, stew etc.
So, how to chop it into portions whilst frozen? Assuming you don't have any CLEAN woodworking tools around, you can try either 1) an electric carving knife or 2) a large, heavy, meat cleaver. A good bread knife might be able to get somewhere.
I would VERY MUCH caution against trying to use a knife to lever the pieces apart. You usually end-up with a piece of meat standing on its edge and one of your hands trying to steady it, then you press the sharp point of a knife with almost as much force as you can muster into the meat. Inevitably, this results in the meat tipping over and the point of the knife slipping off and into your hand very hard.