MoCA adapters can push 175 Mbps, more than enough for the TIVO, or any thing else you are using. Also, you can have more than one receiving adapter.
My opinion, with how fast cable WiFi has gotten, and how good the MoCA adapters work, running CAT cable is a waste of time, unless a few bucks savings is important.
You will need a working router though.
I think you need to have a Tech come out and measure the signal coming into your house, and from the amp, and to you modem.
Our cable company just upgraded from Dos 2.0 to Dos 3.0, and I had to have a Comcast tech come out and do some tweeting to the signal. He said the Dos 3.0 was more sensitive and the signal range had become narrower.
Here is a link to the MoCA adapters, but I would first get the cable WiFi fixed, and then see if you need them.
Actiontec"The ECB2500C MoCA Network Adapter makes it easy for cable broadband subscribers to distribute HD video (and other multimedia content) throughout the home over their existing coaxial cabling. Use the MoCA Network Adapter to bring high-speed Internet connectivity to your gaming consoles, computers and home theater system devices such as an HDTV. These MoCA network adapters are based on the MoCA (Multimedia over Coax Alliance) standard to deliver up to 175 Mbps of bandwidth wherever there's a coaxial port. This means you can finally connect your HDTV to the Internet without stringing Ethernet wires or investing in an expensive rewiring project."
