Changing IP address of remote backup

I set up a remote off-site backup using two EX4100 drives. Everything works correctly. However, because the off-site (destination) location has residential internet service from Verizon, the IP address of the location changes each time the remote router reboots (it gets a new public-facing IP via DHCP–Verizon does not support static IP for residential service). I had hoped that all I would have to do is change the IP address of the remote backup job on the source drive, but I can’t find a way to do this.

The source drive is pretty full (around 1T of data), so a full backup takes several days to complete. Weekly incrementals are much faster since only a small fraction of the 1T is changing.

I’ve explored several options: Creating a new remote backup job each time the IP address changes causes the drives to totally re-copy (meaning the software isn’t smart enough to see that a backup already exists on the remote drive and to sync with that backup). It’s not possible to get a static IP from Verizon so that option is off the table. It’s not possible to use dynamic DNS because the remote backup software uses IP address and not hostname lookup.

All I want is to keep the exact same backup job, just edit it’s destination IP, and have the drive not do a complete re-copy of the entire 1T every time the address changes. Is there any way for me to accomplish this?

Check the most amazing FIFA 2019 APK