Is there a low-level power mode to the I2C.
I am wondering if I should stop the I2C before entering DEEP SLEEP mode using I2C_Stop() and then start it back again on wakeup?
Will this give me any benefit in power?
You can use I2Cin sleep and deep sleep mode. This will help you to save power. Refer to the datasheet link given below to use I2C in low power modes.