In short
Yes, without a car, but it's a chain to respect: bus Chania → Xyloskalo (Omalos) early morning (~€7.50), a 5-7h hike, then ferry Agia Roumeli → Chora Sfakion at 17:30 (Agia Roumeli has no road), and bus Chora Sfakion → Chania at 18:30. Back in Chania around 21:00. ~€35-36 transport in all.