@tzapu another option would be to modify the begin(void) to check to see if begin(sda,scl) was already called and not reset the pins. This way, in your sketch setup you could call Wire.being(sda, scl) before init the adafruit library.
i'm not sure how the WDT detects the time has come in means of code, but I imagine it reads and compares the clock, or has an alarm, so in case of an overflow it might not be made to handle that condition
rst to ground should keep the mcu off, should it not?