I used to do a 27 mile one-way commute, Long Island to Brooklyn. When I was young and racing I could handle this 2-3 days per week. Later years found a park and ride, so took it down to 18 one way, maybe twice per week. Much later would leave car at work, ride home 27, then back in morning, maybe twice per week. NYC was actually the best part as I was on bike lanes and a long paved boardwalk. Nassau County was all back neighborhood streets with constant turning so was the more tiring part.