Paleontologists believe that mammoths averaged about Indian elephant size, on the main. That's RIDICULOUS amounts of meat for one family. Remember the pig slaughtering scene in Little House? Food all winter for four people? Well, if a pig is about 100 pounds, less waste (which they didn't), try 2 tons on for size! Might as well scoop out a hole in the side of the damn thing and live in Chez Dead Tauntaun for the whole of the North Dakotan winter.
And that's just the plains mammoths. The Californian mammoths could get to 16 feet at the shoulder. Ol' Pa Ingalls would need a grenade launcher just to singe the hair off its butt.
(I love mammoths. I especially love our Channel Islands mammoths, which were only 3-4 feet at the shoulder. Mimmoths!)