Personally, I'll take the .357 on humans over the .45 every time in the outdoors from a service sized firearm. Ranges are likely to be longer, .357 revolvers typically are more accurate. I wouldn't worry about getting a bigger caliber. If a big bear threatens, you're going to need your rifle.
I consider the .357 mag, .41 mag, .44 mag, and .45 colt revolvers 40 ounces or less to be among the best sidearms for carry afield, but they do have their limitations in Alaska. I don't understand why anyone would want to carry a sidearm much over 40 ounces. The gun gets that big, you're better off carrying a rifle on a sling. And, if you're hunting, that means you'll have a rifle with you, so why would you want to burden yourself with a .500 Smith? I'd just take the .357 in case you get away from your rifle in camp and need something, but that's the only reason I can think of for even totin' a sidearm up there when you're hunting. I do always like to carry a sidearm when I'm hunting, though, a light, powerful revolver in the above calibers. Only calibers I have, though, are .357 and .45 Colt. Don't have a .44 or .41. They are good calibers, though. Much bigger than .45 Colt/.44 mag and you start getting a gun that is just simply too heavy on the hip. Something the size of my 4 5/8 inch blackhawk or the S&W Mountain gun are about as heavy as I wanna tote all day hunting in rough country, rifle and day pack with me.