If you are more than 30 m (98 ft) away and your G30 is in the line of sight you will still be connected.
Indoors it is approximately 10 m (33 ft), dependent on how many walls in the house etc.
You don’t need to worry though, if you do happen to go out of range, the timer for your brew session will continue, just any changes you make while out of range will only update once back in range.