Your backup is already at hand- your dad and whatever he's packing. If you're going to split up for the hunting, that's another matter.
Canada is death on handguns, so I wouldn't even think of that unless a blackpowder revolver or frontstuffer falls through the legal cracks. My faith in handguns of any sort only runs as deep as the shooting skills of the owner, however. There are some reasonable blackpowder handguns for your needs, but only if they are legal and you're really good with them.
I've faced down half a dozen charges from coastal brown bears over the years, and they're a whole lot bigger than interior griz in Alberta. I was charged for the first time while packing a ML just last year, and it was a religious moment to do so with a single .530 round ball down the pipe.
But I've never had to shoot one. They always stopped at the last moment, then we talked it over for a moment or two, and finally we both backed away. Yeah, attacks do happen, but I have to believe lots of bear killings were bears that would have stopped if folks hadn't started shooting or turned and ran, both of which might encourage an otherwise reluctant bear to finish the job. We'll never know, and one of these days I'm likely to get my posties toasted by a bear that doesn't stop.
Here is info on hunting safety in bear country. There's more on camping and such in bear country when you cruise the site. In my experience most of it is right on. The more you can do to minimize the risk, the less likely you will need the backup.
