If it was a wheel bearing, you would have known in advance from a loud rumbling/roaring noise that wheel would have made (proportional to road speed) while driving.

I have to wonder if it's a collapsed brake line. I had this happen once: after pressing the brakes, residual pressure in the line prevented the caliper from releasing. But after a little while (seconds), pressure will drop off and the brake will start to release. It wasn't enough to lock the wheel, but did cause significant drag on it.