Help with Mail notification

[jrjmpls7]

I had mail notification for years using switch in the mailbox and a wire into the house going to insteon i/o module. But that's quit-probably something ate through the wires. It's a lot of work to replace the wire and I'm almost 80 so it's too much. I'm looking for a wireless way to restore this.
My best idea is to put a Z-Net (I have an extra) in the garage which is fairly close to the mailbox. Then use a z-wave door sensor in the mailbox. But we live in Minnesota and I'm worried that the sensor might not work in the cold or that the battery life might be really bad. Can anyone suggest a solution?
Thanks a lot!!!

[kenm]

There's several YouTube videos on doing this with Z-Wave door sensors. You need to keep the Z-Wave part out of the mailbox otherwise the signal strength will be severely diminished. You'll need to solder a reed switch across the contacts on the Z-Wave assembly and then mount the reed switch inside the mailbox near the magnet. I put the Z-Wave part in a PVC tube with closed ends and mounted it to the backside of the framing that hold the mailbox.

There's a similar thread to this for a gate sensor and I think he was in Minnesota as well. I can't speak for battery nor sensor life in the cold since we seldom get below freezing here in Northern CA.