I've had the problem of frozen windows also, so I'll open the rear door and pull on the front door handle from the inside. Still embarrassing but at least you won't get snow and dirt all over the passenger seat. The only caveat is the door lock will get stuck open occasionally if you open it from the interior and you won't be able to close the door. That's also a possiblity if you open the passenger door normally when it's extremely cold. Once again speaking from experience.