Feb/Mar is a good time to go. As was already posted, it is definately cooler so you'll want to have jackets and rain panchos as it could rain and when it does it tends to be a cold rain.
There are closures for rides/attractions every year during that time, but there are no specifics as yet. Just plan on a fair number being closed.
Keep in mind too that while lines will be shorter, DL doesn't have as many CMs working either. Queues that usually move very quickly will move much more slowly. Fireworks go to weekends only, park hours are shorter, etc.
That said, it is still a very good experience. Just set your expectations appropriately.