Gunks in March will probably be cold, but I've climbed in March. It just depends on if the sun is out or not. 5.10 is a serious grade at the gunks, I suggest starting w/ 7's, 8's and working up, especially if you're not used to trad. Pick up Dick William's Guide at Rock & Snow in New Paltz. Some of my favorite routes:
Jackie 5.5
Madame G's 5.6
High E 5.6
Classic 5.7
Limelight 5.7
Laurel 5.7
Absurdland 5.8
Son of Easy O 5.8
Pas de Deux 5.8
Birdland 5.8
Apoplexy 5.9
Roseland 5.9
Never Never Land 5.10a
Have fun if you go! I'm jealous!