wheel bearings have no set failure pattern.. sometimes you will get the grinding noises, other times you wont. sometimes you can get away with trying to go a bit further on one, other times they bite you in the backside - as this one did.
We had a front wheel bearing on our Dodge pickup do something similar... I had taken the truck on a long trip, and just a few miles before I got home, I noticed it was starting to growl a little - not bad, but just enough to be noticed. Parts got ordered for it.. a couple of days later, we went to pickup a used motorcycle with it & the trailer - was maybe 40 miles round trip... got to where we picked up the bike, no problem, but about 2/3rds of the way home it failed completely - it totally locked up on us. Had to call a friend to come get the trailer, take it home, unload the bike, then come back with the trailer and put the truck on it & take that home. what a day!