Access to CUPS from remote IP


we have a fleet of raspberry Pi 3 on
Each Pi has a printer set up with CUPS.
We would like to be able to access the CUPS GUI from the public IP so we can manage the printer settings remotely.
The problem is that the public IP only supports port 80 that we are already using to run a node.js web server.
Cups default port is 631.
Anyone can suggest the best approach to achieve this?
Many thanks