I fixed the GPS dropped coverage issue on my iPhone 7 with Verizon
I needed to just reset all settings
Go to Settings > General > Reset > Reset All Settings
Be careful NOT to "Erase All Content and Settings"
The "Reset All Settings" keeps all your apps, chat history etc. It erases all your phone settings
I drove over 200 miles over last three days without any dropped coverage. GPS works great
I have voice & data for LTE, no problem. iPhone 7 with Verizon with iOS 10.0.2. Hallelujah - what a pain till now
For what it's worth, I spent bunch of time with Apple tech support earlier this week. They said there's no GPS dropped coverage issue with the iPhone 7, but many users have dropped coverage because of legacy settings. It's an issue for users that restore from backup when setting up new phone