My $.02 worth comes from my experience in a snowbelt in western michigan with lots of everything from wet & heavy to light & fluffy lake effect. A lot of hp is not important as long as time is not important. You simply match ground speed to available hp depending on snow depth and the type of snow. More hp is not only faster, it also uses more fuel. I have been using a 5' front blower with a 6' rear blade on both a 25 or a 35 hp New Holland for the past 30 years. When there is less snow, I angle the rear blade and make quicker work to pull the snow to the sides then finish with the blower. An advantage to the front blower, other than not having to turn your neck around is that the little extra distance from your face to the blower chute seems to reduce the amount of snow dust invariably blown into your face. The only way to totally eliminate that is with a cab.
My last recommendation is to have a snowblower with a 4 blade second stage impeller versus a 3 blade, and a good size (width / diameter) chute. Besides tractor horsepower, the next limiting factor on snowblowing is how quickly the snowblower can get rid of the snow, i.e. get thrown out by the impeller fan and pushed out the chute. 4 blades every revolution versus 3 throw snow easier and the snow is easier to push through a larger width/dia chute. This is more important when the snow is wetter and heavier.
My front blower is run off the tractor's mid pto. A compact tractor in this horsepower range would be way under powered to try running a hydraulic powered snowblower if ever considering that imho.