It seems premature for the wheel bearings to wear out at 50k miles, unless there are other factors involved....

I don't know how cold your "cold" was, but cold can either increase or decrease the tolerance between parts - they either get sloppier or stiffer. In this case, I suspect the cold made bearing wear more noticeable. The grinding noise is certainly one symptom of a loose wheel bearing. I an surprised the shop didn't recommend replacing both while they were in there doing the brakes.

51K miles (was a single owner car, little old couple who mainly drove it on weekends for fun. Only had 21K on it when I picked it up 4yrs ago.)  I just got a front brake job in March, which is when they noticed play in the drivers side bearing, and changed it. I guess the passenger wasn't worn enough to dictate changing at that time?  It's going in the shop on Friday for them to check the right side.

I would agree with this if the brakes (pads and rotors) are in good condition.

How many miles on your MINI?

Might want to check the Front Right wheel bearing...

 Same symptoms as a faulty bearing on the Front Left this summer .   and bearings age together.. if one died on one side. Likely the other side has kicked it too....

Goodluck.

I have weird problem that I want to run by you all, to see if you have seen or heard of this before. I have a 2006 R53, and last fall/winter I got the "trifecta" of abs/slip/tps lights. I checked the codes and had "left front wheel sensor" bad code. I changed that out and it seemed to be fine, but it was just starting to get cold. All last winter I got the three lights about 3-5 minutes into driving, along with a "grinding" noise that seemed to come from under the passenger front dash area, along with a "crunchy" brake pedal for about 50-100ft and then everything was normal (dash lights still on though). I had the car in for an oil change back in March/April and the mechanic said my front left wheel bearing had over an inch of play and was worn out. They changed that and the trifecta of lights went out, and stayed out the entire spring and summer, so I figured that must have really been the issue.

Fast forward to the last two weeks, since it has gotten cold again (40's and lower). I have the trifecta of lights again, AND the crunchy pedal / grinding noise from the front right dash/bonnet area. Seems like it is cold weather related.

Have you ever seen or heard of a cold weather issue like that, maybe the ABS pump sticking/freezing up?