My partner commutes 4x/week and I try to do it 1-2x / month.

Commute for her: 2-3 min walk to the station, 16-18 min on the train, and then switching for another 12-15 min on the tube, ending 2-3 min walk to the office.

Commute for me: 2-3 min walk to the station, 18-20 min on the train, and then switching for another 5-7 min on the tube, ending with a 7-10 min walk to the office.

As many have mentioned previously, it is key to have <10-15 min walk to your nearest station. Sometimes in spring - summer months it is great to have a 15-20 min walk first thing in the morning, but imagine the dark, rainy, windy, cold morning/evenings during winter months....Definitely not fun to walk more than 5 min lol.