For me, I guess it'd depend on how far off plan I went. If it was 150-200 extra cals, even every day of the week, I think I'd just continue with the plan. Extra calories happen, life goes on, not a good idea to feel constant guilt and dwell on it.
If, however, I'm leaning more toward the 500-1000 extra cals every day (not just one day, for which I'd follow the above approach), I think that for me that'd be a sign that I have have some other stuff (likely mental/emotional) that needs to be dealt with before attacking fat loss. In other words, it's entering new territory.
