Saw this post yesterday but I was completely out of popcorn and getting low on beer, so I waited a day to respond.
The bears I have encountered (black bears, no experience with Kodiaks, browns, grizzlies, or polar bears) have generally been rather shy and timid around humans, never had a situation in which I felt particularly threatened. But I never tried to pet the little bear cubs either!
I killed one bear, intentionally, using a shotgun with slugs. Ugliest, nastiest, smelliest, most vermin-infested piece of wild critter I have ever had the displeasure of having to deal with. Never again if I can help it.
No wolves have crossed my path that I am aware of. Plenty of coyotes and a few nasty dogs have been dealt with. None were particularly difficult to kill. Only one really stands out, a Rottweiler about 120 lbs with a 300 lb attitude, took 4 rounds of .45ACP 200-grain JHP (the old Speer "flying ashtrays").
OP says his grandson was deer hunting. I think just about anything suitable for deer will take care of business with black bears or wolves. Wolves tend to live, hunt, and travel in packs, so plenty of ammo might be a good idea. Kind of like walking around most big cities late at night, packs of feral critters looking for the next meal?