Moving my modem to a different room.

Since I can't get a hold of anyone at Xfinity (not even chat), I have to come here.

My modem is set up in the laundry room since it doesn't get too hot in there. It's been the ideal place for it until now. I have someone that is going to start working home and their work is requiring an ethernet connection. If I wanted to have an ethernet cable go from the router to the room she's going to be working in, it's going to have to be over 100 ft long. Instead of that, I was wondering if I could just simply move the modem to that room since it has a coaxial cable coming out of the wall. If I need to do some activation since it's going through a different cable, I am willing to do it. I just want some info from people that have done this since I can't get a hold of anyone at Xfinity (calls kick me to the main menu and chat outright refueses to connect me to someone) and it's really getting on my nerves.