Book a tour on one of the polar bear viewing companies in the area. All the hotels are booked years in advance so they are your best option unless you can find a professional photographer offering a guided tour there.
This Polar Bear was just one of 60 different individuals that I was lucky enough to photograph while I was in Churchill, Manitoba, Canada for nearly as month a few years ago. If you go there make sure you bring your absolute longest lens. A mirrorless system may be your best friend in Churchill too.