The museum is big but you certainly could see a lot in one day. My advice is to NOT go on a weekend this time of year. Pick a day during the week so the crowds will be smaller. Its a great museum
It's way huger than I thought it was. We didn't get through the whole thing. Honestly I can go to the DC museums for free and regret going to that one...
The schools take the kids all the time so I have been with my own school as a student and with my kids classes. And now my colleagues work with the Museum so we have professional connections. Its great.
You should! One word of advice, unless you really want to be in NYC during the Christmas rush you might want to wait until after the holidays. So many tourists in the city! Its sooooo crowded.
March is better than now. April is even better, weather wise. Just don't come during spring break weeks. (Can you tell I am all about avoiding the tourist crowds?)