How crowded is it in the north of Phuket

My wife and I are not really the prime candidates for Phuket. We like nature and don't like crowds and parties. However there are other things we want to do in the area. Some of the boat tpurs, Khao Sok etc. The north (Surin Beach and everything north of that) seems quieter and would be a nice place to stay a while for the beaches.

On the other hand I'm hearing that Thailand is now more crowded than it ever was and tons of accommodations are fully booked. So the question is, what could I expect in that area in terms of crowds if I come in the next few weeks? Maybe mid February.