The good thing is, Premium Connectivity is not required for Sentry Mode, it is only needed for remote viewing of sentry mode and notifications of alarm footage. The recordings will still be on your USB drive, as long as you have sentry mode set to be on.
I have sentry mode on except home.
2 weeks ago, someone bumped into my wife's TM3 at her job (employee parking lot), then ran. I immediately got the notification (my wife doesn't have a desk job) and let her know. We were able to catch the hit and run (they moved to another spot in the parking lot). My wife called the police, and they gave us the information needed to contact the other party's insurance. I had already filed the claim, and their insurance company admitted 100% fault before I even got home to view the higher resolution footage from the drive.
Just so you can get an idea of how much things cost. The body shop only had to repair the bumper cover (plastic weld, sand,...) and paint match. That total was $2,300.