Unlikely to be feasible for gaming as you will run in latency and overhead issues. If you want 60 fps, you have 16-17ms to render each frame.

At the bear minimum, you are probably going to lose a couple of ms from network latency from even the best home networking setups.

Then there is the extra overhead of maintaining state in realtime between multiple systems as well as coordinating what work each system can actual do in parallel. Full set of textures and other data will most certainly need to be on both, as having a shared memory pool across the network would be unfeasible. As a result, you will most likely have the same memory constraints, especially on the gpu, for each machine as you would just using a single machine.