I spent a week fasting and did 30 miles a day plus an hour swim daily. You gotta push through but you can train to do that mileage fasted regularly. Like anything else, you have to train fasted and build up to longer rides.
Now I can smash 30 miles fasted and continue fasting. But in that state you wont be an explosive sprinter. These days I only ride fasted and never eat on rides. But I havent done over 30 in a while. Dont have many issues with bonking.