As MikMo pointed out, I2C is only meant for short distance communication. The distance is largely bound by the line capacitance (up to 400pf) which, depending on the wire you use, is roughly 10 to 20 feet.
That said, it could be useful depending on how long the connection needs to be. RS485 can support a distance up to 40,000 feet so it might be an overkill.