Call Verizon before you leave the US and add Telus cell for $15/month, no change to your plan. Data will be expensive. Minimum cell towers so don't expect coverage as you're driving.
For 9 years I did nothing and had no damage to the toad - but welcome to the Alaskan Highway. Replaced the windshield and have rock damage on the paint. Been a lot of years since we've been to Newfoundland but would expect the same today.
What to do:
1. If you have a rear mud flap near the bumper that is less that 5" from the ground remove it. It will kick up the rocks and it's only purpose is for advertising and marketing anyway.
2. A vertical shield will reflect rocks forward and damage MH paint or radiator. At least put damping material on it. Anything below the shield like a radiator won't be protected.
3. A custom made tight fitting bra works but does require washing every day to remove the dirt under it. Otherwise the paint will be rubbed off.
4. The Protect A Tow type device is the best protection.
5. Cover the side mirrors.
6. When meeting traffic pull over as far as possible and slow way down or better yet stop.
I'd say the MH was hit by about 8-10 rocks from oncoming traffic last year. Truckers were the best as they would pull over as far as possible. RVs and tourists were clueless. The worst were the locals. Rock damage is a way of life and they drove fast.