Being tired after drilling 10 holes in 6 inches of ice baffles me. If that’s the case you need to replace your blades. Takes my 8″ hand Lazer about 10 seconds for a hole like that. Just let the auger do the work, minimal down pressure is needed for a smooth effortless cut, IME.
An 8″ hole removes twice the amount of ice a 6″ hole, which needs to be considered while selecting a cordless drill. You need more foot pounds of torque to remove more ice. Bigger hole=bigger drill=more power to turn the drill and not burn up your drill motor.
Now once ice gets over 18″-20″, an 8″ hand hole becomes a chore after about 5-6 holes. Having said that, if you haven’t purchased anything yet, look for a quality auger (I’d use a Lazer) and find a good deal on a Milwaukee fuel drill and slap a clam plate on it. That’s what my plan is eventually. Until then, hand drilling works fine for what I do.
I’m from central Michigan and we hardly ever get ice over 24″ but a cordless drill setup is cheaper than any electric or gas auger (full price anyways), also lighter and you can use the good cordless drill year round which can be a big selling point. It just helps spread the initial cost a little thinner of buying a several hundred dollar drill, that is if you dont already have one.