5 ft = 1.52 meters
That is long for I2C. It means that the SDA and SCL might cause noise to each other, and perhaps also from the power wires to SDA and SCL.
You need to select the wires in cable for SDA and SCL that has the least influence on each other.
A single wire (not in a cable) for SDA and a single wire for SCL free in the air would be very ugly, but that would work.
As far as I know, the Arduino Wire library has some timeouts, but it is not full proof against I2C bus errors. I have seen a number of propositions to improve it, but none of those are implemented in the library yet.
The I2C is designed to be used within a pcb board, it was never designed to extend it into a cable.