What's the AA on those Mount Hood hops? 3 oz seems like a lot for a 5 gal batch...
My 10 gal doppelbock recipe gets 1 oz of german magnum, 14% AA, for about 18 IBU then I do a very light flavor/aroma later in the boil as well.
A doppelbock in my opinion is all about the malt.
I'd ferment it 50-52 or as low as your yeast suggests, raise for a D rest after 7-8 days then lager as close to freezing as you can for as long as you can stand to wait...haha...longer the better wtih a stronger beer. If you can keep some around that will be awesome in a year or 2.