Best way from Beijing to Sanya in February

We have already booked to fly to Beijing from England, with the intention of some cold weather sightseeing before moving on to Sanya to see our daughter in the Round the World clipper race.

Am I correct to think that flights from Beijing to Sanya at the time will be at premium?
Is Sanya the favorite destination for people in China looking for winter sunshine?

Any recommendations for how to do this trip as reasonably cheaply as possible?