Looking for a hotel in Santorini for the month of March. An 'apartment' style is fine since this is for a family of 5...for a few nights. Most places seem to be closed...please let me know if you're aware of any places open in March. Thanks!

I'm sure Brotherleelove will be along soon, he knows which ones operate all year, there are quite a few.
To help him, where do you want to stay & what is your nightly budget for all of you in euros? That will make a difference to recommendations.

http://www.santorini.com/hotels/allyear.htm

Being five people is not that easy find one well priced and well positioned place to stay in Santorini! I was looking for such an apartment for May but most of them were pretty expensive. After having made a long research, I ended with a an apartment at Blue Dolphins which is in Firostefani, just close to Fira. The price was affordable, at least for me and we have asked for a caldera view apartment. This is where I have found the hotel http://www.santorini-hotels.info/san...Apartments.asp . According to reviews, it looks very good and in general there were good recommendations for it.

Have you checked the weather in March ?