Vienna hybrid - recipe help

Hello everyone. I'm hoping to make a Vienna lager-ish beer, but I'm limited to extract brewing and don't have a spare fridge/freezer for lagering, so... this is my idea. On the advice of a few posters over in the extract brewing forums, I'm going do a partial mash with the Vienna malt, and I've added Carafa special to bring my SRM values up to where I want it. To counter the no lagering capabilities problem, I'm going to use a german ale yeast, and I should be able to ferment it at the lowest end of its preferred temps by putting my primary in water in my cellar.

I've included the recipe I've come up with using hopville's beer calculus - let me know what you think, any advice and comments would be welcome!

3lbs 0oz Vienna Malt
3lbs 0oz Munich Liquid Malt Extract
1lbs 0oz Corn Sugar (Dextrose)
1lbs 0oz Extra Light Dry Extract
0lbs 6oz carafa special I
Batch size: 5.0 gallons

Original Gravity
1.058 / 14.3° Plato

Final Gravity
1.015 / 3.8° Plato

Color
16° SRM / 31° EBC
(Light Brown to Medium Brown)

Hops
boil 60 mins 2.0oz Hallertau leaf 3.1
boil 60 mins 1.75oz Tettnanger leaf 4.5
boil 10 mins 0.75oz Tettnanger leaf 4.5
Boil: 2.5 gallons for 60 minutes


Bitterness
29.3 IBU / 14 HBU
BU:GU
0.50

Yeast
Wyeast German Ale (1007)
ale yeast in liquid form with low flocculation and 75% attenuation


Alcohol
5.7% ABV / 4% ABW
Calories
191 per 12 oz.

Misc
boil 10 min 1 ea Whirlfloc Tablet
boil 10 min 0.8 liquid ozs Yeast Nutrient

I'd skip the corn sugar and use DME in a Vienna lager-ish beer and I'd leave out the carafa. If you really, really, really want a dark color, you could use an ounce or two but it'll be really brown. 6 ounces is way too much.