When I detailed cars a few years back a trick the shop manager taught us was to use liquid tire shine on all the rubber surfaces, seemed to work pretty well. We'd have 50-100 cars on the dealer lot at any time, never had a freezing problem with any of them.

I like to roll all the windows down as far as they'll go, then using a rag I soak the rubber window channel area with the tire shine, use a clean rag to wipe of the excess. Tire shine also works well when applied on the door-jam weather stripping, keeps the doors from freezing shut. Application is the same, soak a rag and apply to the weather stripping.

I like to use a squirt of wd-10 into each of the exterior door lock holes to keep them from freezing. I also soak the latch area and door hinges with wd40 to keep them from freezing too.

Like fonefiddy mentioned, remove all the snow that you possibly can from the vehicle. The snow melts as the vehicle warms up, then the newly melted snow-water seeps into everywhere and refreezes once the vehicle cools off for a long period of time, like sitting over night.