Jerry, I have Spectrum (NYC) and their modem and routers are separate. I had them replace and update both and found that my connections/speeds in other areas of the house were still lousy. I went with Eero mesh network. 2 devices. One in the office/main area with a switch to cover my other connections; and one in the other side of our home. The desktop in the office is connected wirelessly as is the printer. All devices..and there are loads...laptop, iPads, Kindles, over 15 smart switches, Drobo, iRobot........ all work without interruption or issues. This is just from my laptop....
I went with two 6+ routers. The 6 may work for you as well. If one works for you then still worth a try. You can easily add if you wish.