First, this approach is going to fail at some point. Depending on how far away it is, that could be a major issue. It also makes some very bold assumptions about connection speed and latency that are probably not true.

Second, IP doesn’t reliably show location. My cable ISP is typically geolocated to Chicago, despite it being 2 states away. Same for T Mobile connections.

Third, it’s incredibly unlikely that the employer is going to be looking at IP addresses to determine location. Even if they wanted to use tech for this purpose, they would use location services/GPS/etc. Which a VPN won’t conceal.

Fourth, changing the physical mailing address on file would be a bigger flag. But presumably he’ll list that family’s address, which could create other implications.