An interesting question! Compared to most FITD games, I do think it's possible—if you played a single teacher, you could follow the lesson plan rules and make the decisions yourself, which would set up the initial conditions for the fiction of the field trip. The social-based Expertise clearing conditions (the third one for each playbook) will be a little difficult if you're the only one playing, so I'd consider either avoiding those or being generous to yourself about when they would be triggering if other players were present. TTTO doesn't have a pre-built Solo-play mode (it's not a journaling game), but by following the mechanical rules and constructing the fictional state from them, I think you could do it!