Half your luck being in a blizzard! Where were you? I've had my Subaru up to the doors in deep snow for days and never cracked anything.
Turbo drain is not a common source of oil leak. Power steering pump reservoir on early ones is a common leak, rocker covers leak onto the exhaust pretty regularly too. Rear mains and cam and crank seals don't leak as much as people think, it's often the cover at the back that Scott sugested. Best bet is as you mentioned, clean it thoroughly and go for a short drive and re-check it.