I agree with most of above... When in march? How many people? Little kids? That would all play into my answer. We did 4 days our very 1st trip, and had to go back 6 months later because I (and dd) didn't feel like we had enough. I prefer 6 days now, but will do 5 if we have to, and we tend to avoid the most crowded times of the year (see my siggy). But any trip is better than no trip at all, so I would take 4 days if that was the only option!