Is February an okay time to visit Xidi and Hóngcūn? Any thoughts on the Banyan Tree Hotel?

Besides being cold in February, is there also much precipitation? Also, how is the air quality? We are traveling with our 84–year-old mother and would want to avoid icy or slippery conditions as well as bad air pollution if these are givens.

We are thinking of staying at the Banyan Tree Hotel and making day trips from there. We have read some earlier mixed reviews of the property. Do you know if things have smoothed out more recently there?