Since it is a one-time- use product, you will need a substantial roll if you travel to Alaska. Unless of course you rarely remove it from the car when driving.
I did not see any data on the thickness of the material and, like Bernie, wonder if it will stand up to larger pieces of gravel. I doubt if it would do any good on the windshield or headlights, which crack due to impact (momentum) rather than scratch.
Please let us know your experience with this material, since it seems like something that is easy to use and reasonably priced.
For other readers: See www.transitshield.com