While living in the UP for a few years I had two different snow blowers. The first was a used Torro with a 13 hp brigs. The thing was a beast. Could blow snow over 3 ft deep. But it was a beast, the work out you got from trying to manhandle it wore me out. The second blower that I had was a used Yamaha 5 hp. I couldn't clear as much snow as quickly, but was not worn out when I got done. For the size of drive way the OP is talking I would not go larger than a 5hp.