Xfinity modem and my own router

Hello,

My kids started school this  week (video stream into their school) and I'm thinking about renting Xfinity modem in exchange for unlimited data plan.  Question is, is this modem/router powerful enough to cover a 5K squarefoot home (this is including garage area since my Rings and sprinkler are right outside of my garage).  

2nd question, can I hook up my current Netgear Orbi directly into this Xfinity modem so I can take advange of the mesh system (this is needed to cover larger area)?

and thank you in advance for your help.