I'd probably let price decide. I don't think there's much difference weather-wise between early and late Feb, but the fact that we froze on one early March trip and had one very chilly night on another probably clouds my judgment on that count. Winter weather, from mid-Dec to mid-March, is basically a matter of luck in my experience - we've had perfect weather in January and almost too-warm days (high 80s) in December and we've woken up to frost and skipped the fireworks because of the cold in March (two different trips).