10k litre / 1.8m tall water tank sensor

Hi - I have an off-grid shack in Australia with a Victron power setup including a Multiplus + Cerbo. I would like to attach a water sensor (10k litres / 1.8m tall) to my tank (which is 15m from the Cerbo) to alert me when I need to fill up my tank. I have a LAN connection from the tank to the cerbo but i dont think i can connect it to the GX Tank 140. The other option I guess is to find a sensor with a 20m cable, but i cant source one. The other option could be to get a USB extender for 15m… Not sure what cabling comes with the sensors but maybe its easy enough to get some extra cable and extend it and then just have the GX Tank 140 next to the Cerbo? What have others done?