My wife and I have gone to Yosemite Valley nearly every winter in late January/February since 1983, staying at Yosemite Lodge or Curry Village. If you go on weekdays, the rates are more reasonable. There are far, far fewer people in the winter. Hiking around the Valley, we often find ourselves in solitude since many visitors spend the day at Badger Pass skiing. Even in late February, I expect you'll find no crowds except possibly on the weekend.
One bit of advice is don't count on the food available unless you have a lot of time and money. The food court at the Lodge is barely edible and the Mountain Room and Awahnee expensive. We always bring a cooler and our own food.
Have a great time.
