Driving myself home from the hospital.....possible?

No WAY.  You'll be on pain meds for probably a week at least, and it's illegal to be driving on them (not to mention unsafe).  I'm surprised your doc will allow you to go that far away immediately after surgery.  My doc requireed you to stay locally for 2 weeks if you were more than an hour away.  Considering the weather, you may want to consider at least staying there until the weekend when your sister can come get you without missing work.