We stayed at POR Jan 29-Feb 2, 2018. It was the first time we went during that timeframe. I had read that week was “empty” the year before. The resort was full & the parks were definitely not empty. The food court was packed at breakfast everyday, families were walking around with trays of food looking for tables. We hadn’t stayed at POR in years, but It was busier than when we used to stay there in the end of August. I particularly noticed it did not seem to be tour or sports groups, but families.
This year, we were at YC Feb 3-9th. Again, the resort was full, but this is also a deluxe that books up with convention goers, so there are not as many families. The parks were moderately crowded again. I would say crowds levels were 5s- 7s both years. Headliners had typical long waits & we didn’t really experience any real walk ons, except the usual Tiki Room, Peoplemover, Muppets 3D, etc. Things like Spaceship Earth, Pirates & HM had waits well over 30 minutes without FP.
Certainly it isn’t holiday busy, but as PP said, there is always something going on to bring crowds in..... late Jan - early Feb now has the Arts Festival at Epcot. There are sports & cheer competitions many months of the year. And Disney now adjusts staffing based on info gathered from ADR & FP bookings. Expect & plan for moderate crowds at least & if you experience anything less, it will be a pleasant surprise.