If you think there isn't ice in the park here you are sadly mistaken. That shit is firm and I mean FIRM. I'm about 25 to 30lbs less than you. Would I recommend at your size you ride a 54 for powder? No it won't be the most ideal. Would I recommend a 62 to 170 oh fuck no.
Is the pow deep and going to weigh you down here? Nope it's probably the lightest in the country till mid March/April then it can get heavier.