C7800

You can if you disable the wifi radios on the modem and put the MESH into AP mode. 

Or you can add WiFi extenders to the modems wifi signal.

Or you can put the modem into modem only mode and install a MESH system in router mode. 

Netgear has set up a community forum specifically for the Cable Modem products. Most of the people who watch that forum are more likely to have experience with Cable modems:
https://community.netgear.com/t5/Cable-Modems-Routers/bd-p/home-cable-modems-routers

Please use this link to the main forum product list to review and choose where to make your posts. 
https://community.netgear.com/t5/NETGEAR-Forum/ct-p/en-netgear

Thank you.