Looking to leave Videotron, can I use my Helix 2 Borne as a router with another company's modem

I can't find any mentions of this anywhere... How am I able to set up my helix 2 borne as a router only?

I know about bridge mode but that is if I want to use another router and use the helix 2 as a modem.

If I leave Vidéotron will the modem portion of the router stop working as the service is cancelled and the router will keep working? or will the whole thing not work as I am no longer with Vidéotron?

Thank you