I live in Manhattan and my TWC/Spectrum provided Arris TG1672 router/modem combo doesn't provide enough coverage in my small (800 sqft) but concrete walled apartment. I'm thinking about turning off the wifi on the TG1672 and adding a TP-Link Archer C7 wi-fi router. 1) Can I do this? 2) Will this help? 3) How do i do this? Thanks!