An off-track door is not always a dead door. If only one roller has jumped the track and the opener hasn't been forced against it, the door is often still safe to leave down and locked by hand until we get there - we'd rather you not run the opener on it, since that's how a bent track turns into a bent track plus a cracked panel.
We travel from Bedford, roughly 17 miles out, so factor that drive time into how long the door sits before anyone touches it. Once we're on site, a straightforward off-track fix - reseating rollers, squaring a track bracket, replacing a bent section - is usually a same-visit job. If the track itself is badly bent or the door has been run on it repeatedly before the call, the repair takes longer because we're also checking panels, hinges, and cable alignment for damage the initial jump caused.